Structure of the Sun: A Typical Star

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Structure of the Sun A Typical Star
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Layers in the Sun
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Sun Facts

• Diameter 1,390,000 km 109 Earth
  diameters 10 Jupiter diameters
• Mass 1.989 X 1030 kg 333,000 times Earth
• Surface 5600 K
• Core 15,600,000 K
• density 100 X water

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Sun Composition

• By relative number of atoms
• 94 Hydrogen
• 6 Helium
• 0.11 Carbon, Nitrogen, Oxygen
• 0.02 All other elements
• By relative mass
• 78.5 Hydrogen
• 19.7 Helium
• 2 Carbon, Nitrogen, Oxygen
• 0.54 All other elements

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Sunspots

• Regions of strong magnetic field
• 1000-1500 K Lower temperature
• 11 year cycle
• Demonstrates that the sun rotates
• Once every 24 days at equator
• Once every 30 days at poles

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Sunspots
http//antwrp.gsfc.nasa.gov/apod/image/0211/sunspo
t_swedish_c1.jpg
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Coronal Mass Ejections

• Huge bubbles of gas
• Correlate with sunspot cycle

http//solar-center.stanford.edu/weather.html
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Red Visible Light
http//antwrp.gsfc.nasa.gov/apod/image/sun_960515_
big.gif
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Light at Hydrogen Alpha Wavelength

• Granules in the photosphere

http//antwrp.gsfc.nasa.gov/apod/image/0001/sunhal
pha_gendler_big.jpg
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Light at Helium Wavelength

• Granules in the photosphere

http//antwrp.gsfc.nasa.gov/apod/image/0101/hesun_
eit_big.gif
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Light from Highly Charged Fe Atoms

• Images loops in local magnetic fields
• False color image

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An Extreme UV Image of the Sun

• This is a false color image.
• Brightest areas emit the most ultraviolet rays

http//www.wodaski.com/wodaski/images/sun20RGB20
from20extreme20ultraviolet.jpg
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An Extreme UV Image of the Sun

• This is a false color image.
• Red is 2000000 K
• Green is 1500000 K
• Blue is 1000000 K

http//antwrp.gsfc.nasa.gov/apod/image/0006/sun3co
l_thompsoneit.jpg
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An X-ray Image of the Sun

• This is a false color image.
• Brightest areas emit the most X-rays
• Corona shows area above surface is 1000000 K

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The Corona
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Solar Wind

• Mostly protons and electrons
• 4 days to travel to Earth
• Velocity of 400 Km/s (500000 mph)
• 1 million tons of matter/second ejected
• 10 particles/cm3 vs air 1018 particles/cm3
• Deflected by Earths magnetic field

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Solar Weather Report
http//sec.noaa.gov/ace/MAG_SWEPAM_7d.html