3. The Sun Our Sun Classification: G Temperature: 6000 K Age: 6 Billion Years Old Composition 73.4% Hydrogen 73.4% Hydrogen 25% Helium 25% Helium

4. The Sun Sun’s Layers The Solar Interior The Solar Interior Visible Surface Visible Surface Photopshere Photopshere Atmospheric AtmosphericChromosphereCorona

5. Sun’s Atmosphere

6. Sun’s Surface Features The Fusion Process of the Sun Provides the Sun with Violent Surface Features Sunspots Magnetic Fields Coronal Mass Ejections

7. Sun

8. Photosphere Photosphere Photos = Light Photos = Light Sphere = Ball Sphere = Ball 500 km Thick 500 km Thick Grainy Texture (Size of Texas) Grainy Texture (Size of Texas) Composition is revealed by the dark lines in absorption spectrum Composition is revealed by the dark lines in absorption spectrum

9. Solar Granules

11. What Causes the Granule Look? Convection Currents

12. Sunspots Sunspots Darker Areas Surrounding Hotter Areas Temporary Features May Last Days, Weeks, or Months May Last Days, Weeks, or MonthsCyclic 10-11 year Patten 10-11 year Patten Increase and Decrease in Frequency Increase and Decrease in Frequency Solar Activity Cylce Solar Activity Cylce

13. How Do Sunspots Develop

15. Magnetic Field Sunspots are Related to Magnetic Field Magnetic Fields cause prominences Huge arching gas columns Huge arching gas columns Violent eruptions near a sunspot are called solar flares

16. Sun’s Atmosphere The Sun’s Atmosphere has Two Layers Chromosphere 2000 km above Photosphere 2000 km above PhotosphereCorona Extends millions of miles into space Extends millions of miles into space Temp as high as 2 Million Degrees Kelvin Temp as high as 2 Million Degrees Kelvin Particles are released as Solar Wind Particles are released as Solar Wind

17. Chromosphere Chromosphere A relatively thin layer of hot gases a thousand km thick A relatively thin layer of hot gases a thousand km thick Can be seen during a solar eclipse Can be seen during a solar eclipse Produces an emission spectrum Produces an emission spectrum

18. Corona Corona Outermost portion of the solar atmosphere Outermost portion of the solar atmosphere Can be seen during a solar eclipse Can be seen during a solar eclipse Extends a few a thousand km into space Extends a few a thousand km into space Creates the solar wind Creates the solar wind 1 million degrees K 1 million degrees K

19. Solar Flares Are brief outburst that normally last about an hour Are brief outburst that normally last about an hour appear as a sudden brightening of the region above a sunspot cluster appear as a sudden brightening of the region above a sunspot cluster Produces Auroras Produces Auroras

20. Solar Prominences

22. Solar Flare

23. Coronal Mass Ejection Bright, appear as a halo around the Sun when emitted in the Earth’s Direction Highly Charged Solar Wind Particles can disrupt radio signals (cell phones) Near Earth Polar Areas Solar wind can create light Northern Lights Northern Lights

26. Northern Lights

27. Causes of the Northern Lights

28. Northern Lights

29. Color of the Aurora

30. Fun Facts of the Aurora Brilliant auroras often occur at 27-day intervals as active areas on the sun's surface face earth during its 27-day rotation cycle. Northern lights are more frequent in late autumn and early spring. October, February and March are the best months for auroral observations in northern Norway. Northern lights activity corresponds closely to sunspot activity, which follows an 11-year cycle, but there seems to be a one-year delay between sunspot maximum and maximum auroral occurrence. Northern lights activity is 20-30% less during solar minimum than at solar maximum.

31. Fun Facts Continued Andenes, Norway Almost every dark and clear night Fairbanks, Alaska Five to ten times a month Oslo, Norway Roughly three nights a month Northern Scotland, Great Britain Roughly once a month US/Canadian border Two to four times a year Mexico and Mediterranean countries Once or twice a decade South of the Mediterranean countries Once or twice a century Equator Once in two hundred years

32. Sun’s Interior The Ultimate Power Plant Nuclear Fusion Coverts four H atoms into the nucleus of a Helium atom Coverts four H atoms into the nucleus of a Helium atom Internal temp. needs to be several million degrees Internal temp. needs to be several million degrees Where does the temp come from? Where does the temp come from? Compression of the gases that form the sun Increase Pressure = Increase Temperature

33. Production of Energy Nuclear Fusion Joining of Atoms Proton – Proton Chain Starts with two Protons and Ends with Helium Starts with two Protons and Ends with Helium ENERGY ENERGY