1. The Sun and Stars Lesson 2 pg. 808
The Sun (Our Enemy)
The Sun and Stars
Lesson 2 pg. 808

2. How Stars Shine pg. 809
1. Describe nuclear fusion: A process that occurs when the nuclei of several atoms combine into one larger nucleus (2 hydrogen atoms combine to form 1 helium atom)

3. 2. Star- A large ball of gas held together by gravity with a core so hot that nuclear fusion occurs.

4. Composition and Structure of Stars - Interior
3. Core: Where the energy from the sun is produced through nuclear fusion.

5. 4. Radiative zone: A shell of cooler hydrogen above a star’s core
4. Radiative zone: A shell of cooler hydrogen above a star’s core. (Energy takes more than 100,000 years to move through this layer because it is so dense.)
5. Convection zone: Where hot
gas moves up toward the
surface and cooler gas
moves deeper into the interior.

6. Atmosphere of Stars
6. What is the photosphere? The apparent surface of a star
7. Describe the chromosphere: The orange-red layer above the photosphere
8. Corona- The wide,
outermost layer above
the photosphere.

8. The Sun’s Changing features pg. 810
9. What does it mean when the book says that the sun is dynamic? It is always changing
10. Describe sunspots: regions of magnetic activity that are cooler than the rest of the photosphere. They follow a cycle peaking in number every 11 years.

9. 11. What is a prominence? Clouds of gas that make loops and jets extending into the corona.

10. 12. Describe a solar flare: Sudden increases of brightness often found near sunspots.
13. What is a coronal mass ejection? Huge bubbles of gas ejected from the corona. Larger than solar flares. Material can reach earth causing the malfunction of electronic equipment.

11. 14. Solar winds: Charged particles that stream continually away from the sun. The Earth’s magnetic field protects it from the solar winds. (Causes the Auroras)

15. Fun Facts:
The sun accounts for 99% of the entire mass of the solar system.
You can fit 1 million Earths inside the sun.
Temperatures inside the sun can reach 15 million degrees.
The sun is 432,288 miles across. (The Earth is 24,902 miles across)
Light takes more than 100,000 years to move through the radiative zone. So light that goes into your eye started its journey 100,000 years ago!