1. Do Now 12/9/09 What is the sun made of???
ON YOUR BLUE SHEET
What is the sun made of???
Write down a couple of facts you know about our Sun

2. The Sun

3. Sunny Facts Sun is an ordinary star
Center of our solar system making life possible on Earth
An enormous ball of gas fusing hydrogen into helium in its core
Energy produced travels outward through radiation and convection zone where it swirls and then emitted into space
Sunny Facts

4. Photosphere is the lowest layer of sun’s atmosphere and where light is given off
Temperature is about 6,000 K
Chromosphere is above photosphere and 2,000 km thick
Sun’s Atmosphere

5. Corona is between 2,000 km and 10,000 km above the photosphere
Largest layer of the Sun’s atmosphere extending millions of km into space
Temperatures reach as high as 2 million K
Charged particles escape as solar wind
Sun’s Atmosphere

6. Suns Processes
Thermonuclear fusion: two or more atomic nuclei collide at a very high speed and join to form a new type of atomic nucleus.
Radiation: energy that comes from a source and travels through some material or through space
Convection: transfer of heat from one place to another by the movement of fluids

8. Using the diagram
1. Where in the sun does nuclear fusion occur? 2. What conditions in this part of the sun’s interior causes nuclear fusion to happen?

9. 3. How does the energy produced by nuclear fusion escape the sun. 4
3. How does the energy produced by nuclear fusion escape the sun? 4. How does energy move through the sun’s radiative zone? 5. What function does the sun’s convective zone perform?

10. Surface Features
Sunspots appear as dark areas on Sun because they are cooler
Lasts days, weeks, or months
Observing sunspots led to the discovery that the sun rotates on an axis

11. Surface Features
Rotation at equator takes 25 days and at poles 33 days
Sunspots are cyclical with maximum activity every 10 to 11 years

12. Magnetic fields at sunspots may cause Prominences on Sun’s surface
Huge arched columns of gas blasted into space 600 km/s to 1,000 km/s
At times violent eruptions at sunspots cause Solar Flares to shoot outward at high speeds
Surface Features

13. Surface Features
Coronal Mass Ejections (CME) occurs during maximum sunspot activity
Appears as a halo around the sun
High solar winds, Ultraviolet light and X-rays can reach Earth and cause problems with radio signals
Ionized gas causes aurora on Earth at poles