7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 143

983124983144983141 983123983157983150

983118983157983154 983113983155983148983137983149983145

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 243

983113983118983124983122983119983108983125983107983124983113983119983118

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 343

Visible Image of the SunThe SunThe Sun

bullOur sole sourceof light and heat in

the solar s stem

bullA very common

star a glowing ball of

gas held together by its

own gravity and powered

by nuclear fusion at its

center

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 443

Pressure (from heat

caused by nuclearreactions) balances the

gravitational pull

toward the Sunrsquos center

Called ldquoHydrostatic

Equilibrium

spherical ball of gascalled the Sun

What would happen if

the nuclear reactions

(ldquoburningrdquo) stopped

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 543

983123983119983116983105983122 983120983122983119983120983109983122983124983113983109983123

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 643

Radius = 696000 km

(100 times Earth)

Mass = 2 x 1030 kg

(300000 times Earth)

Av Density = 1410 kgm3

Rotation Period =

Solar PropertiesSolar Properties

249 days (equator)298 days (poles)

Surface temp = 5780 K

Element

Hydrogen 709

Helium 274etc

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 743

Luminosity of the Sun

= LSUN

(Total light energy

emitted per second)

~ 4 x 1026 W100 billion one-

megaton nuclear bombs

every second

Solar constant

LSUN 4πR2

(energysecondarea

at the radius of

Earthrsquos orbit)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 843

The Solar InteriorldquoHelioseismologyrdquo

bullIn the 1960s it was

discovered that thesurface of the Sunvibrates like a bell

How do we know the interiorHow do we know the interior

structure of the Sunstructure of the Sun

bullInternal pressurewaves reflect off thephotosphere

bullAnalysis of thesurface patterns ofthese waves tell usabout the inside of the

Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 943

The Standard Solar Model

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1043

Energy Transport within the Sun

bull Extremely hot core - ionized gas

bull Temperature falls further from core - more and more non-ionized atoms

capture the photons - gas becomes opaque to light in the convection zone

bull The low density in the photosphere makes it transparent to light - radiation

takes over again

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1143

Convection

Convection takes over when

the gas is too opaque for

radiative energy transport

Hot gas is less dense and

rises (or ldquofloatsrdquo like a hot air

balloon or a beach ball in a

pool)

Cool gas is more dense and

sinks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1243

Solar Granulation

Evidence for Convection

Solar Granules are the tops of convection cells

Bright regions are where hot material is upwelling(1000 km across)

Dark regions are where cooler material is sinking

Material risessinks ~1 kmsec (2200 mph Doppler)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1343

983124983112983109 983123983125983118 983105983124983117983119983123983120983112983109983122983109

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1443

The solar spectrum has

thousands of absorption

lines

More than 67 different

elements are present

The Solar Atmosphere

Hydrogen is the mostabundant element followed

by Helium (1st discovered

in the Sun)

Spectral lines only tell us about the part of the Sun that forms

them (photosphere and chromosphere) but these elements are

also thought to be representative of the entire Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 243

983113983118983124983122983119983108983125983107983124983113983119983118

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 343

Visible Image of the SunThe SunThe Sun

bullOur sole sourceof light and heat in

the solar s stem

bullA very common

star a glowing ball of

gas held together by its

own gravity and powered

by nuclear fusion at its

center

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 443

Pressure (from heat

caused by nuclearreactions) balances the

gravitational pull

toward the Sunrsquos center

Called ldquoHydrostatic

Equilibrium

spherical ball of gascalled the Sun

What would happen if

the nuclear reactions

(ldquoburningrdquo) stopped

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 543

983123983119983116983105983122 983120983122983119983120983109983122983124983113983109983123

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 643

Radius = 696000 km

(100 times Earth)

Mass = 2 x 1030 kg

(300000 times Earth)

Av Density = 1410 kgm3

Rotation Period =

Solar PropertiesSolar Properties

249 days (equator)298 days (poles)

Surface temp = 5780 K

Element

Hydrogen 709

Helium 274etc

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 743

Luminosity of the Sun

= LSUN

(Total light energy

emitted per second)

~ 4 x 1026 W100 billion one-

megaton nuclear bombs

every second

Solar constant

LSUN 4πR2

(energysecondarea

at the radius of

Earthrsquos orbit)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 843

The Solar InteriorldquoHelioseismologyrdquo

bullIn the 1960s it was

discovered that thesurface of the Sunvibrates like a bell

How do we know the interiorHow do we know the interior

structure of the Sunstructure of the Sun

bullInternal pressurewaves reflect off thephotosphere

bullAnalysis of thesurface patterns ofthese waves tell usabout the inside of the

Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 943

The Standard Solar Model

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1043

Energy Transport within the Sun

bull Extremely hot core - ionized gas

bull Temperature falls further from core - more and more non-ionized atoms

capture the photons - gas becomes opaque to light in the convection zone

bull The low density in the photosphere makes it transparent to light - radiation

takes over again

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1143

Convection

Convection takes over when

the gas is too opaque for

radiative energy transport

Hot gas is less dense and

rises (or ldquofloatsrdquo like a hot air

balloon or a beach ball in a

pool)

Cool gas is more dense and

sinks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1243

Solar Granulation

Evidence for Convection

Solar Granules are the tops of convection cells

Bright regions are where hot material is upwelling(1000 km across)

Dark regions are where cooler material is sinking

Material risessinks ~1 kmsec (2200 mph Doppler)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1343

983124983112983109 983123983125983118 983105983124983117983119983123983120983112983109983122983109

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1443

The solar spectrum has

thousands of absorption

lines

More than 67 different

elements are present

The Solar Atmosphere

Hydrogen is the mostabundant element followed

by Helium (1st discovered

in the Sun)

Spectral lines only tell us about the part of the Sun that forms

them (photosphere and chromosphere) but these elements are

also thought to be representative of the entire Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 343

Visible Image of the SunThe SunThe Sun

bullOur sole sourceof light and heat in

the solar s stem

bullA very common

star a glowing ball of

gas held together by its

own gravity and powered

by nuclear fusion at its

center

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 443

Pressure (from heat

caused by nuclearreactions) balances the

gravitational pull

toward the Sunrsquos center

Called ldquoHydrostatic

Equilibrium

spherical ball of gascalled the Sun

What would happen if

the nuclear reactions

(ldquoburningrdquo) stopped

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 543

983123983119983116983105983122 983120983122983119983120983109983122983124983113983109983123

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 643

Radius = 696000 km

(100 times Earth)

Mass = 2 x 1030 kg

(300000 times Earth)

Av Density = 1410 kgm3

Rotation Period =

Solar PropertiesSolar Properties

249 days (equator)298 days (poles)

Surface temp = 5780 K

Element

Hydrogen 709

Helium 274etc

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 743

Luminosity of the Sun

= LSUN

(Total light energy

emitted per second)

~ 4 x 1026 W100 billion one-

megaton nuclear bombs

every second

Solar constant

LSUN 4πR2

(energysecondarea

at the radius of

Earthrsquos orbit)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 843

The Solar InteriorldquoHelioseismologyrdquo

bullIn the 1960s it was

discovered that thesurface of the Sunvibrates like a bell

How do we know the interiorHow do we know the interior

structure of the Sunstructure of the Sun

bullInternal pressurewaves reflect off thephotosphere

bullAnalysis of thesurface patterns ofthese waves tell usabout the inside of the

Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 943

The Standard Solar Model

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1043

Energy Transport within the Sun

bull Extremely hot core - ionized gas

bull Temperature falls further from core - more and more non-ionized atoms

capture the photons - gas becomes opaque to light in the convection zone

bull The low density in the photosphere makes it transparent to light - radiation

takes over again

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1143

Convection

Convection takes over when

the gas is too opaque for

radiative energy transport

Hot gas is less dense and

rises (or ldquofloatsrdquo like a hot air

balloon or a beach ball in a

pool)

Cool gas is more dense and

sinks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1243

Solar Granulation

Evidence for Convection

Solar Granules are the tops of convection cells

Bright regions are where hot material is upwelling(1000 km across)

Dark regions are where cooler material is sinking

Material risessinks ~1 kmsec (2200 mph Doppler)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1343

983124983112983109 983123983125983118 983105983124983117983119983123983120983112983109983122983109

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1443

The solar spectrum has

thousands of absorption

lines

More than 67 different

elements are present

The Solar Atmosphere

Hydrogen is the mostabundant element followed

by Helium (1st discovered

in the Sun)

Spectral lines only tell us about the part of the Sun that forms

them (photosphere and chromosphere) but these elements are

also thought to be representative of the entire Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 443

Pressure (from heat

caused by nuclearreactions) balances the

gravitational pull

toward the Sunrsquos center

Called ldquoHydrostatic

Equilibrium

spherical ball of gascalled the Sun

What would happen if

the nuclear reactions

(ldquoburningrdquo) stopped

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 543

983123983119983116983105983122 983120983122983119983120983109983122983124983113983109983123

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 643

Radius = 696000 km

(100 times Earth)

Mass = 2 x 1030 kg

(300000 times Earth)

Av Density = 1410 kgm3

Rotation Period =

Solar PropertiesSolar Properties

249 days (equator)298 days (poles)

Surface temp = 5780 K

Element

Hydrogen 709

Helium 274etc

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 743

Luminosity of the Sun

= LSUN

(Total light energy

emitted per second)

~ 4 x 1026 W100 billion one-

megaton nuclear bombs

every second

Solar constant

LSUN 4πR2

(energysecondarea

at the radius of

Earthrsquos orbit)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 843

The Solar InteriorldquoHelioseismologyrdquo

bullIn the 1960s it was

discovered that thesurface of the Sunvibrates like a bell

How do we know the interiorHow do we know the interior

structure of the Sunstructure of the Sun

bullInternal pressurewaves reflect off thephotosphere

bullAnalysis of thesurface patterns ofthese waves tell usabout the inside of the

Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 943

The Standard Solar Model

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1043

Energy Transport within the Sun

bull Extremely hot core - ionized gas

bull Temperature falls further from core - more and more non-ionized atoms

capture the photons - gas becomes opaque to light in the convection zone

bull The low density in the photosphere makes it transparent to light - radiation

takes over again

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1143

Convection

Convection takes over when

the gas is too opaque for

radiative energy transport

Hot gas is less dense and

rises (or ldquofloatsrdquo like a hot air

balloon or a beach ball in a

pool)

Cool gas is more dense and

sinks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1243

Solar Granulation

Evidence for Convection

Solar Granules are the tops of convection cells

Bright regions are where hot material is upwelling(1000 km across)

Dark regions are where cooler material is sinking

Material risessinks ~1 kmsec (2200 mph Doppler)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1343

983124983112983109 983123983125983118 983105983124983117983119983123983120983112983109983122983109

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1443

The solar spectrum has

thousands of absorption

lines

More than 67 different

elements are present

The Solar Atmosphere

Hydrogen is the mostabundant element followed

by Helium (1st discovered

in the Sun)

Spectral lines only tell us about the part of the Sun that forms

them (photosphere and chromosphere) but these elements are

also thought to be representative of the entire Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 543

983123983119983116983105983122 983120983122983119983120983109983122983124983113983109983123

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 643

Radius = 696000 km

(100 times Earth)

Mass = 2 x 1030 kg

(300000 times Earth)

Av Density = 1410 kgm3

Rotation Period =

Solar PropertiesSolar Properties

249 days (equator)298 days (poles)

Surface temp = 5780 K

Element

Hydrogen 709

Helium 274etc

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 743

Luminosity of the Sun

= LSUN

(Total light energy

emitted per second)

~ 4 x 1026 W100 billion one-

megaton nuclear bombs

every second

Solar constant

LSUN 4πR2

(energysecondarea

at the radius of

Earthrsquos orbit)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 843

The Solar InteriorldquoHelioseismologyrdquo

bullIn the 1960s it was

discovered that thesurface of the Sunvibrates like a bell

How do we know the interiorHow do we know the interior

structure of the Sunstructure of the Sun

bullInternal pressurewaves reflect off thephotosphere

bullAnalysis of thesurface patterns ofthese waves tell usabout the inside of the

Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 943

The Standard Solar Model

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1043

Energy Transport within the Sun

bull Extremely hot core - ionized gas

bull Temperature falls further from core - more and more non-ionized atoms

capture the photons - gas becomes opaque to light in the convection zone

bull The low density in the photosphere makes it transparent to light - radiation

takes over again

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1143

Convection

Convection takes over when

the gas is too opaque for

radiative energy transport

Hot gas is less dense and

rises (or ldquofloatsrdquo like a hot air

balloon or a beach ball in a

pool)

Cool gas is more dense and

sinks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1243

Solar Granulation

Evidence for Convection

Solar Granules are the tops of convection cells

Bright regions are where hot material is upwelling(1000 km across)

Dark regions are where cooler material is sinking

Material risessinks ~1 kmsec (2200 mph Doppler)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1343

983124983112983109 983123983125983118 983105983124983117983119983123983120983112983109983122983109

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1443

The solar spectrum has

thousands of absorption

lines

More than 67 different

elements are present

The Solar Atmosphere

Hydrogen is the mostabundant element followed

by Helium (1st discovered

in the Sun)

Spectral lines only tell us about the part of the Sun that forms

them (photosphere and chromosphere) but these elements are

also thought to be representative of the entire Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 643

Radius = 696000 km

(100 times Earth)

Mass = 2 x 1030 kg

(300000 times Earth)

Av Density = 1410 kgm3

Rotation Period =

Solar PropertiesSolar Properties

249 days (equator)298 days (poles)

Surface temp = 5780 K

Element

Hydrogen 709

Helium 274etc

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 743

Luminosity of the Sun

= LSUN

(Total light energy

emitted per second)

~ 4 x 1026 W100 billion one-

megaton nuclear bombs

every second

Solar constant

LSUN 4πR2

(energysecondarea

at the radius of

Earthrsquos orbit)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 843

The Solar InteriorldquoHelioseismologyrdquo

bullIn the 1960s it was

discovered that thesurface of the Sunvibrates like a bell

How do we know the interiorHow do we know the interior

structure of the Sunstructure of the Sun

bullInternal pressurewaves reflect off thephotosphere

bullAnalysis of thesurface patterns ofthese waves tell usabout the inside of the

Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 943

The Standard Solar Model

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1043

Energy Transport within the Sun

bull Extremely hot core - ionized gas

bull Temperature falls further from core - more and more non-ionized atoms

capture the photons - gas becomes opaque to light in the convection zone

bull The low density in the photosphere makes it transparent to light - radiation

takes over again

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1143

Convection

Convection takes over when

the gas is too opaque for

radiative energy transport

Hot gas is less dense and

rises (or ldquofloatsrdquo like a hot air

balloon or a beach ball in a

pool)

Cool gas is more dense and

sinks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1243

Solar Granulation

Evidence for Convection

Solar Granules are the tops of convection cells

Bright regions are where hot material is upwelling(1000 km across)

Dark regions are where cooler material is sinking

Material risessinks ~1 kmsec (2200 mph Doppler)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1343

983124983112983109 983123983125983118 983105983124983117983119983123983120983112983109983122983109

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1443

The solar spectrum has

thousands of absorption

lines

More than 67 different

elements are present

The Solar Atmosphere

Hydrogen is the mostabundant element followed

by Helium (1st discovered

in the Sun)

Spectral lines only tell us about the part of the Sun that forms

them (photosphere and chromosphere) but these elements are

also thought to be representative of the entire Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 743

Luminosity of the Sun

= LSUN

(Total light energy

emitted per second)

~ 4 x 1026 W100 billion one-

megaton nuclear bombs

every second

Solar constant

LSUN 4πR2

(energysecondarea

at the radius of

Earthrsquos orbit)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 843

The Solar InteriorldquoHelioseismologyrdquo

bullIn the 1960s it was

discovered that thesurface of the Sunvibrates like a bell

How do we know the interiorHow do we know the interior

structure of the Sunstructure of the Sun

bullInternal pressurewaves reflect off thephotosphere

bullAnalysis of thesurface patterns ofthese waves tell usabout the inside of the

Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 943

The Standard Solar Model

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1043

Energy Transport within the Sun

bull Extremely hot core - ionized gas

bull Temperature falls further from core - more and more non-ionized atoms

capture the photons - gas becomes opaque to light in the convection zone

bull The low density in the photosphere makes it transparent to light - radiation

takes over again

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1143

Convection

Convection takes over when

the gas is too opaque for

radiative energy transport

Hot gas is less dense and

rises (or ldquofloatsrdquo like a hot air

balloon or a beach ball in a

pool)

Cool gas is more dense and

sinks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1243

Solar Granulation

Evidence for Convection

Solar Granules are the tops of convection cells

Bright regions are where hot material is upwelling(1000 km across)

Dark regions are where cooler material is sinking

Material risessinks ~1 kmsec (2200 mph Doppler)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1343

983124983112983109 983123983125983118 983105983124983117983119983123983120983112983109983122983109

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1443

The solar spectrum has

thousands of absorption

lines

More than 67 different

elements are present

The Solar Atmosphere

Hydrogen is the mostabundant element followed

by Helium (1st discovered

in the Sun)

Spectral lines only tell us about the part of the Sun that forms

them (photosphere and chromosphere) but these elements are

also thought to be representative of the entire Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 843

The Solar InteriorldquoHelioseismologyrdquo

bullIn the 1960s it was

discovered that thesurface of the Sunvibrates like a bell

How do we know the interiorHow do we know the interior

structure of the Sunstructure of the Sun

bullInternal pressurewaves reflect off thephotosphere

bullAnalysis of thesurface patterns ofthese waves tell usabout the inside of the

Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 943

The Standard Solar Model

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1043

Energy Transport within the Sun

bull Extremely hot core - ionized gas

bull Temperature falls further from core - more and more non-ionized atoms

capture the photons - gas becomes opaque to light in the convection zone

bull The low density in the photosphere makes it transparent to light - radiation

takes over again

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1143

Convection

Convection takes over when

the gas is too opaque for

radiative energy transport

Hot gas is less dense and

rises (or ldquofloatsrdquo like a hot air

balloon or a beach ball in a

pool)

Cool gas is more dense and

sinks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1243

Solar Granulation

Evidence for Convection

Solar Granules are the tops of convection cells

Bright regions are where hot material is upwelling(1000 km across)

Dark regions are where cooler material is sinking

Material risessinks ~1 kmsec (2200 mph Doppler)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1343

983124983112983109 983123983125983118 983105983124983117983119983123983120983112983109983122983109

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1443

The solar spectrum has

thousands of absorption

lines

More than 67 different

elements are present

The Solar Atmosphere

Hydrogen is the mostabundant element followed

by Helium (1st discovered

in the Sun)

Spectral lines only tell us about the part of the Sun that forms

them (photosphere and chromosphere) but these elements are

also thought to be representative of the entire Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 943

The Standard Solar Model

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1043

Energy Transport within the Sun

bull Extremely hot core - ionized gas

bull Temperature falls further from core - more and more non-ionized atoms

capture the photons - gas becomes opaque to light in the convection zone

bull The low density in the photosphere makes it transparent to light - radiation

takes over again

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1143

Convection

Convection takes over when

the gas is too opaque for

radiative energy transport

Hot gas is less dense and

rises (or ldquofloatsrdquo like a hot air

balloon or a beach ball in a

pool)

Cool gas is more dense and

sinks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1243

Solar Granulation

Evidence for Convection

Solar Granules are the tops of convection cells

Bright regions are where hot material is upwelling(1000 km across)

Dark regions are where cooler material is sinking

Material risessinks ~1 kmsec (2200 mph Doppler)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1343

983124983112983109 983123983125983118 983105983124983117983119983123983120983112983109983122983109

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1443

The solar spectrum has

thousands of absorption

lines

More than 67 different

elements are present

The Solar Atmosphere

Hydrogen is the mostabundant element followed

by Helium (1st discovered

in the Sun)

Spectral lines only tell us about the part of the Sun that forms

them (photosphere and chromosphere) but these elements are

also thought to be representative of the entire Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1043

Energy Transport within the Sun

bull Extremely hot core - ionized gas

bull Temperature falls further from core - more and more non-ionized atoms

capture the photons - gas becomes opaque to light in the convection zone

bull The low density in the photosphere makes it transparent to light - radiation

takes over again

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1143

Convection

Convection takes over when

the gas is too opaque for

radiative energy transport

Hot gas is less dense and

rises (or ldquofloatsrdquo like a hot air

balloon or a beach ball in a

pool)

Cool gas is more dense and

sinks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1243

Solar Granulation

Evidence for Convection

Solar Granules are the tops of convection cells

Bright regions are where hot material is upwelling(1000 km across)

Dark regions are where cooler material is sinking

Material risessinks ~1 kmsec (2200 mph Doppler)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1343

983124983112983109 983123983125983118 983105983124983117983119983123983120983112983109983122983109

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1443

The solar spectrum has

thousands of absorption

lines

More than 67 different

elements are present

The Solar Atmosphere

Hydrogen is the mostabundant element followed

by Helium (1st discovered

in the Sun)

Spectral lines only tell us about the part of the Sun that forms

them (photosphere and chromosphere) but these elements are

also thought to be representative of the entire Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1143

Convection

Convection takes over when

the gas is too opaque for

radiative energy transport

Hot gas is less dense and

rises (or ldquofloatsrdquo like a hot air

balloon or a beach ball in a

pool)

Cool gas is more dense and

sinks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1243

Solar Granulation

Evidence for Convection

Solar Granules are the tops of convection cells

Bright regions are where hot material is upwelling(1000 km across)

Dark regions are where cooler material is sinking

Material risessinks ~1 kmsec (2200 mph Doppler)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1343

983124983112983109 983123983125983118 983105983124983117983119983123983120983112983109983122983109

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1443

The solar spectrum has

thousands of absorption

lines

More than 67 different

elements are present

The Solar Atmosphere

Hydrogen is the mostabundant element followed

by Helium (1st discovered

in the Sun)

Spectral lines only tell us about the part of the Sun that forms

them (photosphere and chromosphere) but these elements are

also thought to be representative of the entire Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1243

Solar Granulation

Evidence for Convection

Solar Granules are the tops of convection cells

Bright regions are where hot material is upwelling(1000 km across)

Dark regions are where cooler material is sinking

Material risessinks ~1 kmsec (2200 mph Doppler)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1343

983124983112983109 983123983125983118 983105983124983117983119983123983120983112983109983122983109

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1443

The solar spectrum has

thousands of absorption

lines

More than 67 different

elements are present

The Solar Atmosphere

Hydrogen is the mostabundant element followed

by Helium (1st discovered

in the Sun)

Spectral lines only tell us about the part of the Sun that forms

them (photosphere and chromosphere) but these elements are

also thought to be representative of the entire Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1343

983124983112983109 983123983125983118 983105983124983117983119983123983120983112983109983122983109

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1443

The solar spectrum has

thousands of absorption

lines

More than 67 different

elements are present

The Solar Atmosphere

Hydrogen is the mostabundant element followed

by Helium (1st discovered

in the Sun)

Spectral lines only tell us about the part of the Sun that forms

them (photosphere and chromosphere) but these elements are

also thought to be representative of the entire Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1443

The solar spectrum has

thousands of absorption

lines

More than 67 different

elements are present

The Solar Atmosphere

Hydrogen is the mostabundant element followed

by Helium (1st discovered

in the Sun)

Spectral lines only tell us about the part of the Sun that forms

them (photosphere and chromosphere) but these elements are

also thought to be representative of the entire Sun

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1543

Main Regions of the Sun

Visible

surface

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1643

983124983144983141 983120983144983151983156983151983155983152983144983141983154983141

bull 983124983144983141 983158983145983155983145983138983148983141 983155983157983154983142983137983139983141 983151983142 983156983144983141 983155983157983150

bull 983113983156 983145983155 983150983151983156 983155983151983148983145983140 983156983144983145983150 983148983137983161983141983154 983151983142 983143983137983155 983148983141983155983155 983156983144983137983150 98309300

983147983149 983140983141983141983152

bull 983141 983152983151983156 983151983155983152 983141983154983141 983155 983141983155983155 983156 983137983150 983137983155 983141983150983155983141983137983155 983156983144983141 983137983145983154 983145983150 983156983144983141 983141983137983154983156983144

bull 983106983141983148983151983159 983152983144983151983156983151983155983152983144983141983154983141 983156983144983141 983143983137983155 983145983155 983140983141983150983155983141983154 983137983150983140

983144983151983156983156983141983154

bull 983124983144983141 983143983154983137983150983157983148983137983156983145983151983150 983145983155 983137983152983152983141983137983154 983145983150 983156983144983141 983152983144983151983156983151983155983152983144983141983154983141

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1743

GranulesConvection from inside the sun causes the

photosphere to be subdivided into 1000-

2000km cells

Energy rises to the surface as gas wells up in the cores of

the granules and cool gas sinks around their edges

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1843

Chromosphere

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 1943

Chromosphere (seen during full Solar eclipse)

Chromosphere emits very little light because it is of low density

Reddish hue due to 3rarr2 (6563 nm) line emission from Hydrogen

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2043

bull 983124983144983141 983139983144983154983151983149983151983155983152983144983141983154983141991257983155 983140983141983150983155983145983156983161 983154983137983150983143983141983155 983142983154983151983149

10000983085100 983138983145983148983148983145983151983150 983156983145983149983141983155 983148983141983155983155 983156983144983137983150 983156983144983141 983137983145983154 983151983150983156983144983141 983141983137983154983156983144

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2143

Chromospheric Spicules

warm jets of matter

shooting out at ~100 kms

Spicules are thought to theresult of magnetic

disturbances

Hα light

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2243

Transition Zone and Corona

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2343

Transition Zone

amp Corona

We see emission

lines from highly

Very low density

T ~ 106 K

Why does the Temperature rise further from the hot light source

ionized elements(Fe+5 ndash Fe+13) which

indicates that the

temperature here is

very HOT

rarr magnetic ldquoactivityrdquo -spicules and other more energetic

phenomena (more about this laterhellip)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2443

Corona (seen during full Solar eclipse)

Hot coronal gas

escapes the Sun

rarr Solar wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2543

Solar Wind

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2643

Solar Wind

Coronal gas has enough heat (kinetic) energy to escape theSunrsquos gravity

The Sun is evaporating via this ldquowindrdquo

Solar wind travels at ~500 kms reaching Earth in ~3 days

The Sun loses about 1 million tons of matter each second

However over the Sunrsquos lifetime it has lost only ~01 of

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2743

Hot coronal gas (~1000000 K) emits mostly in X-rays

Coronal holes

are sources of

the solar wind

(lower density

regions)

Coronal holes

are related to the

Sunrsquos magneticfield

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2843

The Active Sun

UV light

Most of theSolar luminosity is continuous photosphere emission

But there is an irregular component

(contributing little to the Sunrsquos total luminosity)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 2943

983123983125983118983123983120983119983124

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3043

Sunspots

Granulation around sunspot

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3143

SunspotsSunspotsbull Typically about 10000 km

across

bull At any time the sun may

have hundreds or none

bull

are cooler than photosphericgas (4500K in darkest parts)

bull Each spot can last from a few days to a few months

bull Galileo observed these spots and realized the sun is rotatingdifferentially (faster at the poles slower at the equator)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3243

Sunspots amp

Magnetic Fields

bullThe magnetic field in a sunspot

is 1000x greater than the

surrounding area

bullSunspots are almost always in

pairs at the same latitude with

each member having opposite

polarity

bullAll sunspots in the same

hemisphere have the same

magnetic configuration

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3343

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3443

The Sunrsquos differential rotation distorts the magnetic field lines

The twisted and tangled field lines occasionally get kinked causing the field

strength to increase

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3543

Sunspot Cycle

Solar maximum is

reached every ~11 years

Solar Cycle is 22 years long ndash direction of magnetic field

polarity flips every 11 years (back to original orientation every 22 years)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3643

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3743

Charged particles (mostly

protons and electrons) are

accelerated along magnetic field

ldquolinesrdquo above sunspots

This type of activity not light

Heating of the Corona

Ch d ti l f ll ti fi ld b t t

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3843

Charged particles follow magnetic fields between sunspots

Solar Prominences

Sunspots are cool

but the gas abovethem is hot

S l P i

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 3943

Earth

Solar ProminenceTypical size is 100000 km

May persist for days or weeks

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4043

Very large solar prominence (12 million km across base

ie 39 Earth diameters) taken from Skylab in UV light

S l Fl

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4143

Solar Flares ndash much more violent magnetic instabilities

5 hours

Particles in the flare are so energetic the magnetic field cannot bring themback to the Sun ndash they escape Sunrsquos gravity

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4243

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)

7212019 2 The Sunpdf

httpslidepdfcomreaderfull2-the-sunpdf 4343

983124983137983155983147 983090bull 983117983137983147983141 983151983150983141 983152983137983152983141983154 (983091983085983093 983152983137983143983141983155) 983156983144983137983156 983140983145983155983139983157983155983155

983137983138983151983157983156983098 983118983157983139983148983141983137983154 983142983157983155983145983151983150 983145983150 983156983144983141 983155983157983150 983137983150983140 983145983156983155983145983149983152983148983145983139983137983156983145983151983150

bull 983119983150983141 983143983154983151983157983152 (983139983144983151983155983141983150 983154983137983150983140983151983149983148983161) 983159983145983148983148 983152983154983141983155983141983150983156 983145983156

983159983145983156983144983145983150 9830900 983149983145983150983157983156983141983155 (1983093 983149983145983150983157983156983141983155 983142983151983154

983152983154983141983155983141983150983156983137983156983145983151983150 + 983093 983149983145983150983157983156983141983155 983121amp983105)