The Sun – El Sol – Die Sonne

1. The Sun – El Sol – Die Sonne ESPS- Palmer High School

2. Interesting Facts about the sun • http://www.bing.com/videos/search?q=Sun&FORM=HDRSC3#view=detail&mid=F72C15A1770A0A936D5FF72C15A1770A0A936D5F

3. How big is the sun? • About 110 times wider than Earth • 1.3 million times bigger than Earth • Sun is 865 thousand miles wide

4. Composition of the sun (what is it made of?) • Contains 99.8% of the entire mass of Solar System • Earth’sprimary source of energy • Made of Gases (what 2 types of gases?) • Hydrogen 70% • Helium 28%

5. How does the sun produce energy? • The Sun produces energy by the nuclear fusion of hydrogen into helium in its core. http://www.youtube.com/watch?v=4iyS2WmT9NM

6. Inside of the sun • Core • Radiative Zone • Convection zone

7. Nuclear Fusion • hydrogen atoms in the core are crushed together (fused) into a helium atom • This energy is then radiated out from the core and moves across the solar system. • This is radiation (gamma rays)

8. Hydrogen yields Helium + ENERGY Great Pressure

10. How does our Sun compare to other Stars? • Active stars range in size from supergiants to dwarfs- Our sun is a dwarf with medium mass • Stars range from very bright (supergiants) to very dim (dwarfs)-Our Sun is a medium-bright dwarf • Stars range from very hot blue on the outside (O class) to cool red on the outside (M class)-Our Sun is in-between--yellow

12. The Sun’s Atmosphere • Photosphere- the photosphere may be thought of as the imaginary surface from which the solar light that we see appears to be emitted. • Chromosphere- The chromosphere is an irregular layer above the photosphere where the temperature rises from 6000°C to about 20,000°C. At these higher temperatures hydrogen emits light that gives off a reddish color • Corona- This extended outer atmosphere of the Sun has a temperature of millions of degrees, but it is 10 billion times less dense than the atmosphere of the Earth at sea level.

13. Features of the sun continued… • Solar Flares occur at times in complex sunspot groups, they are abrupt, violent explosions from the sun. Solar flares are thought to be caused by sudden magnetic field changes in areas where the sun's magnetic field is concentrated. They're accompanied by the release of gas, electrons, visible light, ultraviolet light and X-rays. When this radiation and these particles reach the Earth's magnetic field, they interact with it at the poles to produce the auroras (borealis and australis). Solar flares can also disrupt communications, satellites, navigation systems and even power grids

14. Features of the sun • Sun Spots- These are dark, cool areas that appear on the photosphere. Sunspots always appear in pairs and are intense magnetic fields (about 5,000 times greater than the Earth's magnetic field) that break through the surface. Caused by movement of gases.

15. Sun features continued….CME’s • coronal mass ejections. • ­Clouds of gases from the chromosphere will rise and orient themselves along the magnetic lines from sunspot pairs and form arches called prominences. • Prominences can erupt for hours and send large amounts of charged material racing through the corona and outward into space at 600 miles per second (1,000 kilometers per second) • These eruptions of material are called Coronal Mass Ejections

16. So is our Sun an average star? • No—most stars are smaller and cooler than our Sun BUT • Most of the bright stars we see are bigger and hotter http://www.treehugger.com/slideshows/natural-sciences/12-most-amazing-time-lapse-videos-stars-landscapes-and-urban-scenes/page/3/#slide-top

17. Features of the sun continued… Solar Wind • Blows charged particles and magnetic fields away from the Sun • Charged particles captured by Earth’s magnetic field • Create Auroras or Northern and Southern Lights • Electrons from solar wind are captured by the Earth’s magnetic field • Interact with atoms in our atmosphere: oxygen and nitrogen make red and green; nitrogen can also make violet • Northern lights are Aurora Borealis, while southern are Aurora Australis Auroras http://sohowww.nascom.nasa.gov/bestofsoho/Movies/animation/Solarwind.mpg

18. Coronal Mass Ejection (CME’s) • CME is a massive burst of solar wind and magnetic fields rising above the solar corona or being released into space • Effects of CME • Can damage satellites • Very dangerous to astronauts • Power problems This series of images of coronal mass ejections taken with LASCO C3 (May 1-31, 1997) at http://sohowww.nascom.nasa.gov/bestofsoho/Movies/C3May97/C3May97sm.mpg

19. How does the sun affect the Earth? • Gravity- Orbits- The Sun’s powerful gravity keeps the planets in orbit • Radiation- Our Sun (and all active stars) emits radiation Radio, infrared, visible, ultraviolet, x-ray and even some gamma rays. Most of the sunlight is yellow-green visible light or close to it The Earth’s atmosphere filters out some frequencies Ozone layer protects us from some ultra-violet, and most x-rays and gamma rays Water and oxygen absorb some radio waves Water vapor, carbon dioxide, and ozone absorbs some infrared • Sunlight is absorbed by Earth The Sun does NOT send “heat rays” into space. Some of its light is infrared, but that is not the same thing as heat. The Sun’s light is absorbed by Earth (clouds, plants, oceans, rock…) By absorbing the light, we are transforming it into heat energy