1. California Standards: 1a, e.
The Sun
California Standards: 1a, e.

3. Sun’s Energy
The sun, and most other stars, gets its energy from the fusion of atoms within it core.
Hydrogen is the main source of fuel for stars.
Hydrogen is fused into helium at extremely high temperatures, such as 15,000,000o C.

4. Energy Source for the Stars
Energy is produced by the fusion of hydrogen into helium in the core of the sun.
This takes place at 10,000,000 degrees Kelvin or 10,000,000o K
Other elements are created also such as calcium, iron, etc.
Occurs when temperature and pressure are great enough.

5. Fusion of Hydrogen in the Sun
E = mc2

7. Composition of the Sun Each star has its specific “signature”.
Just as humans have finger prints, stars have specific signatures that are determined by a spectrograph or a graph which shows what gases or elements are found in that star.

8. Spectrograph for hydrogen against a stars spectrograph.

9. The Sun’s Interior
The interior of the sun is divided into three sections.
The core is where extremely high temperatures and pressures create the conditions for fusion.
The radiative zone is where energy moves outward.
The convection zone where energy is transferred to the sun atmosphere.

10. The Sun’s Atmosphere
The photosphere is where much of the visible light given off by the sun originates.
The temperature is about 6,000o C
The dark spots of the photosphere are called sun spots whose temperature is a cool 3,800o C

11. The Sun’s Interior

12. Structure of the Sun A. _____________ B. _____________
D. ____________
E. ____________
F. ____________

13. Solar Activity The sun in nothing more than a ball of hot gases.
The sun rotates every 27 days on average.
Sunspots are cooler than the rest of the sun and have a cycle of 11 years.

14. Features of the Sun Sunspots are cool areas of the sun
They are not permanent but can last for days before disappearing.
Cycle over 11 year period

15. Photosphere
Sun spots in the photosphere

16. Sunspots

18. Sunspot Activity

19. Sunspot activity, 11 year cycle

21. Solar Ejections Prominences are clouds of gases that form huge arches.
Solar flares are a sudden outward eruption of electrically charged particles.
Coronal Mass Ejections are particles that are thrown into space and cause geomagnetic storms on Earth.

22. Solar Prominences

23. Solar Flare
Earth

24. Earth’s Magnetic Field
Earth has a magnetic field caused by the movement of it’s iron-nickel core.
This magnetic field protects Earth from radiation emitted from our sun.
This magnetic field gives rise to auroras at the North and South poles.

26. Earth’s Magnetic Field

27. Coronal Mass Ejections (CMEs)
CMEs are solar hurricanes that
send out magnetic bubbles
thousands of kilometers across filled with
billion-ton plasma clouds
at millions of kilometers per hour.

28. Coronal Mass Ejections

29. Coronal Mass Ejections
Coronal mass ejections result in particles striking our magnetosphere surrounding the Earth.
This results in geomagnetic storms which result in auroras that are called the Northern Lights.

30. Coronal Mass Ejections

33. Northern Lights or Aurora

34. All stars are not alike. 1. The sun is a small star
2. The sun is called a main sequence star. Meaning that it is just an average star in size and age.
3. There are much larger stars in the universe.
4. These larger stars are called supergiants.

35. How large is our Sun?
supergiant

37. Current Solar Reseach
National Aeronautic and Space Administration (NASA) launched a new satellite.
The new satellite is called STEREO, Solar TErrestrial RElations Observatory which uses two satellites to observe the sun.
For the first time these satellites provide a 3-D view of the sun.

38. STEREO satellites

40. Here Comes the Sun