The Sun

•a medium sized star•93,000,000 miles away

•109 times diameter of Earth•1 million Earths could fit in the Sun•Made of gas: 82% hydrogen, 17%

helium, 1% other•99% of mass of solar system

•26 day rotation

Our Sun compared to other suns!

Our Sun compared to other even larger suns!

Layers of the Sun• Core• 27 million degrees F• Fusion, the process that gives

the sun energy occurs here• Photosphere• made of hydrogen gas• layer that we see glowing yellow• 9000 degrees F• Chromosphere• inner atmospheric glowing

red layer of ionized hydrogen gas

• Corona• thin outer atmosphere• extends millions of kilometers• seen as halo during solar eclipse

Corona seen during solar eclipse

Sunspots

• an area on the sun that has extremely strong magnetic activity

• magnetic activity does NOT allow heat movement so it is a cool region

• looks like a dark spot• last 2 weeks• occur in 11 year cycles

Each sunspot is larger than Earth.They produce solar flares.

Sunspots usually occur in pairs in 11 year cycles.

Sunspot activity since 1760

Recent sunspot activity

Solar Flares – eruptions of hot gas that sends ions (charged particles) and radiation

into space to create the solar wind

Solar Flares

Close Up of Flares

Prominence – streamers of hot gases

Coronal Mass Ejections

• eruptions of tons of high energy particles

Solar Wind – a continuous flow of charged particles from the sun into space

Solar Dynamics

Observatory launch on 2/11/10 on an Atlas V

Rocket

SDO on its way toward the Sun