How did it form? Basic facts

99.8% of mass 100x diameter of Earth 5,527oC 92.1% H, 7.8% He Plasma Sun today Main source of Earth’s

energy

Our Sun

http://www.nasa.gov/images/content/524990main_FAQ10_full.jpg

Need to know! Thermal energy Temperature Heat

3 Types of heat Occur in different parts of the Sun1. Conduction

Core Dense, hottest

Hydrogen fusion

How do we get the Sun’s energy?

Light waves How energy gets to Earth

Radiation Zone Energy moves slowly

Thick layer

2. Radiation

3. Convection

In liquids and gases Material heated

(conduction) Rises….why? Sinks….why? Repeat

Convection Zone Moves more

quickly in this layer

Inner Solar Structure Review

Core

Radiation Zone

Convection Zone

Photosphere Visible surface

Chromosphere Temp. increases Red glow

Corona Outermost layer Very hot Seen during an eclipse

Outer Solar Structure

What is a magnetic field?

What causes a magnetic field? On the Sun?

Effect of rotation Different rotation rates Magnetic field lines get

wound up Eventually snap

Sun’s Magnetic Field

http://www.cbsnews.com/8301-205_162-57597396/

Intense magnetic field prevents convection.

Cooler than nearby areas Appear in pairs Brightness & temp.

Sunspots

http://oneminuteastronomer.com/1018/sunspots/

Predictable cycle 11-years Minimums

Last = 2008/2009

Low # of prominences, flares and sunspots

Cooler climate on Earth

Last maximum = 2013

Sunspot Cycle

http://academic.emporia.edu/aberjame/student/johnson5/sunspotcycle.html

Solar flares Caused by field snap High energy Explosive

Prominence Loops/arches Follow magnetic field lines into space

Surface Features

Solar Wind Plasma stream Hot, high speed

Coronal Mass Ejections (CME) Massive eruption Rearrangement of magnetic field lines Recent CMEs

Effects on Earth Disrupt magnetic field shape Damage electronics Danger to astronauts

Solar Wind & CME

http://stereo.gsfc.nasa.gov/browse/2013/10/14/index.shtml

Interaction of particles and magnetic field Particles drawn to

poles Colors

Elements Altitude

Constantly changing

Borealis or Australis

Video

Aurora

http://www.public.iastate.edu/~sdk/fick2003/october.html