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Astronomy Unit 2: Stars and Galaxies. What is the relationship between the milky way, our solar system, the universe and Earth ?. Our Place in the Universe. Stars and Galaxies Astronomy Unit 2. Vocabulary. universe : everything that exists in space, including all matter and energy - PowerPoint PPT Presentation
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Astronomy Unit 2:Stars and Galaxies
• What is the relationship between the milky way, our solar system, the universe and Earth ?
The Universe
Our GalaxyThe Milkyway
Our Solar System
The Earth
Our Place in the Universe
Our Solar System• Planets• Dwarf Planet
Galaxies• 3 types• Elliptical• Spiral • Irregular
Distances• Lightyears • exactly 9,460,730,472,580.8 km (about 9.5 Pm)• about 5,878,625,373,183.6 miles (about 6 trillion miles)
Stars• Life Cycle of Stars• Classification of Stars: Hertzsprung-Russel Diagram• Our Sun• Black Hole• Nebula
Stars and Galaxies Astronomy Unit 2
Voca
bula
ry• universe: everything that exists in space, including all matter and energy
• galaxy: a large group of stars, space dust, and gases held together by gravity
• Milky Way: the galaxy in which the Sun is located
• star: a massive ball of hot gases that emits its own light
• Sun: the medium-sized star in the center of the system of objects in space that
includes Earth
• nebula: a cloud of space dust that can clump together to form a star; the plural of
nebula is nebulae (Star Nursery or Stellar Nursery)
• Hertzsprung-Russell (H-R) diagram: a diagram that displays the relationship
between a star’s surface temperature and its magnitude, or brightness
• luminosity: a measure of the energy released each second from the surface of a
star (Brightness)
“Earthrise” 1968
Earthrise is the name given to a photograph of the Earth taken by astronaut William Anders in
1968 during the Apollo 8 mission. It has been called "the most influential environmental
photograph ever taken."
Our Solar System
• Which planet do you find interesting?
Relative Size of Planets Space School Video
2012 Venus Transit
Partial Solar Eclipse
Planet Comparrison
http://www.youtube.com/watch?v=ZYVKcDvokiM
The Milky Way Galaxy
• 100,000 light years in diameter• Our sun orbits the center of the
galaxy once every 240 million years
• A Barred spiral galaxy• Contains over 200 billion stars• It is our home galaxy
The Milky Way Galaxy ViewerThis picture, which combines infrared images taken by two different telescopes, shows 1 billion of the Milky Way galaxy's stars all at once.CREDIT: Mike Read (WFAU), UKIDSS/GPS and VVVView full size image
What is at the center of the milky way?
Galactic Center of the Milky Way • Super massive black hole at the center
Simulated view of a black hole in front of the Large Magellanic Cloud.CREDIT: Alain R. | Wikimedia Commons
How can you see a black hole?
Black Hole
An artist's drawing shows a large black hole pulling gas away from a nearby star. Image Credit: NASA E/PO, Sonoma State University, Aurore Simonnet
• A black hole is a place in space where gravity pulls so much that even light can not get out.
• The gravity is so strong because matter has been squeezed into a tiny space.
• This can happen when a star is dying.
Types of Galaxies
• Galaxy: A large group of stars, gas, and dust held together by gravity.
Elliptical Galaxies
• Elliptical Galaxies: Most common type of galaxy; large three-dimensional football shaped galaxies.-Contain mostly older and dimmer stars.
Spiral Galaxies• Spiral Galaxies:
Circular galaxies that have arms curve outward from a central hub.
• Contain a super massive black hole at the center
• The Milky Way is a Spiral Galaxy
Spiral Galaxies
• Spiral Galaxies: Circular galaxies that have arms curve outward from a central hub.
• Barred spiral galaxies: Have two spiral arms extending out.
Irregular Galaxies
• Irregular Galaxies: Come in many different shapes and are smaller and less common than elliptical or spiral galaxies.
Light year
Lightyears
How far is the Moon from the Earth ? 1.3 light seconds.How far is the Earth from the Sun ? 500 light seconds or 8 light minutes.
light year: a unit of length equal to the distance that light travels in one year
In space, light travels at a speed of nearly 300,000 kilometers per second, or almost 9.5 trillion kilometers per year. A light year is thus equal to about 9.5 trillion kilometers.
Lightyears• When you measure distances on Earth, you
typically use units such as meters or kilometers. The distance to most stars, however, is so large that these units are not practical. Instead, scientists use a unit called a light year to measure distances in space. One light year is the distance that light travels in one year. In space, light travels at a speed of nearly 300,000 kilometers per second, or almost 9.5 trillion kilometers per year. A light year is thus equal to about 9.5 trillion kilometers.
• After our Sun, the nearest star to Earth is Proxima Centauri. This star is a little more than 4.2 light years (40 trillion kilometers) away. The distance to a star or galaxy in light years is equal to the number of years needed for the light from that object to reach an observer on Earth. Light from Proxima Centauri takes a little more than 4.2 years to reach Earth. If you observe this star tonight, you would see Proxima Centauri as it looked 4.2 years ago. You will not see what this star looks like at this very moment until 4.2 years from now.
LightyearsWhat does a light year measure?
How many kilometers in a lightyear?
How far is the Moon from the Earth ?
How far is the Earth from the Sun ?
How far is the Earth from the next nearest star, Proxima Centauri?
LightyearsWhat does a light year measure?
How many kilometers in a lightyear?
How far is the Moon from the Earth ?
How far is the Earth from the Sun ?
How far is the Earth from the next nearest star, Proxima Centauri?
LightyearsWhat does a light year measure?
How many kilometers in a lightyear?
How far is the Moon from the Earth ?
How far is the Earth from the Sun ?
How far is the Earth from the next nearest star, Proxima Centauri?
LightyearsWhat does a light year measure?
How many kilometers in a lightyear?
How far is the Moon from the Earth ?
How far is the Earth from the Sun ?
How far is the Earth from the next nearest star, Proxima Centauri?
Units of DistanceSection
Range (m)Unit Example Items≥ <
Subatomic 0 10−15 am electron, quark, string, Planck length
Atomic to cellular
10−15 10−12 fm proton, neutron10−12 10−9 pm wavelength of gamma rays and X-rays, hydrogen atom
10−9 10−6 nm DNA helix, virus, wavelength of optical spectrum
Human scale
10−6 10−3 µm bacterium, fog water droplet, human hair[1]
10−3 100 mm mosquito, golf ball, football100 103 m human being, football field, Eiffel Tower
103 106 km Mount Everest, length of Panama Canal, larger asteroid
Astronomical
106 109 Mm the Moon, Earth, one light-second109 1012 Gm Sun, one light-minute, Earth's orbit1012 1015 Tm orbits of outer planets, Solar System1015 1018 Pm one light-year; distance to Proxima Centauri1018 1021 Em galactic arm1021 1024 Zm Milky Way, distance to Andromeda Galaxy1024 ∞ Ym visible universe
Scale of the Universe
• The Scale of the Universe• The Scale of the Universe Video• http://www.atlasoftheuniverse.com/
Stars
Stars
star: a massive ball of hot gases that emits its own light
Our Galaxy: The Milky Way Galaxy
Our Sun and The Earth
The Sun is our closest Star
• Sun: the medium-sized star in the center of the system of objects in space that includes Earth
Our _________ is a ________________-sized star near the edge of a ___________ galaxy named ____________________.
Our Sun is many thousands of times closer to Earth than any other star.
Our _________ is a ________________-sized star near the edge of a ___________ galaxy named ____________________.
Our Sun is many thousands of times closer to Earth than any other star.
Our _________ is a ________________-sized star near the edge of a ___________ galaxy named ____________________.
Our Sun is many thousands of times closer to Earth than any other star.
Our _________ is a ________________-sized star near the edge of a ___________ galaxy named ____________________.
Our Sun is many thousands of times closer to Earth than any other star.
Anatomy of the Sun
Video About the Sun
Hubble
http://www.youtube.com/watch?v=mcBV-cXVWFw
Lifecycle of Star
Hertzprung Russell Diagram
Nebula –
Horsehead Nebula
Pillars of Creation in the Eagle Nebula
nebula: a cloud of space dust that can clump together to form a star; the plural of nebula is nebulae
Stellar Nursery
Space Cats
Video about Pillars of Creation
Average Star and Massive Stars
Red Giant
White Dwarf
Red Super giant
Supernova
• SupernovaBLAST FROM THE PAST: Type IIn supernovae are believed to represent the collapse of massive stars surrounded by dense shrouds. Eta Carinae in the Milky Way is shown for illustration; it is a massive star (or pair of stars) surrounded by a nebula of material it cast off in the past.
Neutron Stars
A very small dense star that is composed mostly of tightly-packed neutrons (neutronium).
The Crab Nebula
Life Cycle Stars
Massive Star Main Sequence Star
Our Sun is medium sized main sequence star
Life Cycle of Stars
Hertzsprung – Russell Diagram
Hotter
Brighter
Hertzsprung – Russell Diagram
• Hertzsprung-Russell (H-R) diagram is used to classify stars
_____________ - ____________ Diagram
_____________ - ____________ Diagram_____________ - ____________ Diagram
_____________ - ____________ Diagram
___________- _________ Diagram ___________- _________ Diagram
___________- _________ Diagram ___________- _________ Diagram
Glue Nows
Star Type #4
Star Type #3
Star Type #2
Star Type #1
_____________________________________DiagramUsed to classify stars
Do N
ow!!
!!
universe: everything that exists in space, including all matter
and energy
galaxy: a large group of stars, space dust, and gases held
together by gravity
Milky Way: the galaxy in which the Sun is located
star: a massive ball of hot gases that emits its own light
Sun: the medium-sized star in the center of the system of
objects in space that includes Earth
nebula: a cloud of space dust that can clump together to form a
star; the plural of nebula is nebulae
Hertzsprung-Russell (H-R) diagram: a diagram that displays the
relationship between a star’s surface temperature and its
magnitude, or brightness
luminosity: a measure of the energy released each second from
the surface of a star
light year: a unit of length equal to the distance that light
travels in one year
Astronomy Unit 2 Vocabulary
universe: everything that exists in space, including all matter
and energy
galaxy: a large group of stars, space dust, and gases held
together by gravity
Milky Way: the galaxy in which the Sun is located
star: a massive ball of hot gases that emits its own light
Sun: the medium-sized star in the center of the system of
objects in space that includes Earth
nebula: a cloud of space dust that can clump together to form a
star; the plural of nebula is nebulae
Hertzsprung-Russell (H-R) diagram: a diagram that displays the
relationship between a star’s surface temperature and its
magnitude, or brightness
luminosity: a measure of the energy released each second from
the surface of a star
light year: a unit of length equal to the distance that light
travels in one year
Astronomy Unit 2 Vocabulary
__________________________
__________________________
__________________________
__________________________
__________________________
__________________________
__________________________
__________________________
__________________________
__________________________
__________________________
__________________________
__________________________
__________________________
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Planets Inner Rocky Planets1.2.3.4.Asteroid BeltGaseous Giants5.6.Ice Giants7.8.Dwarf Planets9.
Planets Inner Rocky Planets1.2.3.4.Asteroid BeltGaseous Giants5.6.Ice Giants7.8.Dwarf Planets9.
PlanetsInner Rocky Planets1.2.3.4.Asteroid BeltGaseous Giants5.6.Ice Giants7.8.Dwarf Planets9.
PlanetsInner Rocky Planets1.2.3.4.Asteroid BeltGaseous Giants5.6.Ice Giants7.8.Dwarf Planets9.
Our _________ is a ________________-sized star near the edge of a ___________ galaxy named ____________________.
Our Sun is many thousands of times closer to Earth than any other star;
Our _________ is a ________________-sized star near the edge of a ___________ galaxy named ____________________.
Our Sun is many thousands of times closer to Earth than any other star;
SectionRange (m)
Unit Example Items≥ <
Subatomic 0 10−15 am electron, quark, string, Planck length
Atomic to cellular
10−15 10−12 fm proton, neutron
10−12 10−9 pm wavelength of gamma rays and X-rays, hydrogen atom
10−9 10−6 nm DNA helix, virus, wavelength of optical spectrum
Human scale
10−6 10−3 µm bacterium, fog water droplet, human hair[1]
10−3 100 mm mosquito, golf ball, football
100 103 m human being, football field, Eiffel Tower
103 106 km Mount Everest, length of Panama Canal, larger asteroid
Astronomical
106 109 Mm the Moon, Earth, one light-second
109 1012 Gm Sun, one light-minute, Earth's orbit
1012 1015 Tm orbits of outer planets, Solar System
1015 1018 Pm one light-year; distance to Proxima Centauri
1018 1021 Em galactic arm
1021 1024 Zm Milky Way, distance to Andromeda Galaxy
1024 ∞ Ym visible universe
SectionRange (m)
Unit Example Items≥ <
Subatomic 0 10−15 am electron, quark, string, Planck length
Atomic to cellular
10−15 10−12 fm proton, neutron
10−12 10−9 pm wavelength of gamma rays and X-rays, hydrogen atom
10−9 10−6 nm DNA helix, virus, wavelength of optical spectrum
Human scale
10−6 10−3 µm bacterium, fog water droplet, human hair[1]
10−3 100 mm mosquito, golf ball, football
100 103 m human being, football field, Eiffel Tower
103 106 km Mount Everest, length of Panama Canal, larger asteroid
Astronomical
106 109 Mm the Moon, Earth, one light-second
109 1012 Gm Sun, one light-minute, Earth's orbit
1012 1015 Tm orbits of outer planets, Solar System
1015 1018 Pm one light-year; distance to Proxima Centauri
1018 1021 Em galactic arm
1021 1024 Zm Milky Way, distance to Andromeda Galaxy
1024 ∞ Ym visible universe
Elliptical
Spiral
Irregular
Elliptical
Spiral
Irregular
• Hertzsprung-Russell (H-R) diagram: a diagram that displays the relationship between a star’s surface temperature and its magnitude, or brightness
Hertzsprung – Russell Diagram
