2. Star Structure Diagram (Draw this)

3. Star Structure The sun, like all stars, is made up of hydrogen and helium gases, and a handful of other elements depending on age/origin of star. Newer stars will have more “metals”. These are heavier elements than can be thought of as used fuel.

4. The Core (15,000,000 ° C): Fuels the sun's “shine”, made entirely of gases. Very dense. Responsible for fusing Hydrogen to Helium. Radiation Zone: Photons move outward from core in a series of absorptions and emissions. This may be a very slow process, as this area is still quite dense. Convection Zone: Photons continue to travel to the surface. In this area, hotter gases rise and cooler gas sinks in a manner similar to that of gas bubbles rising in boiling water. Surface/Photosphere: outer layer of gases, much cooler than the rest of the sun.

5. Solar Atmosphere Chromosphere: thin and spiky layer of gas outside the surface of the sun. During eclipses, the chromosphere can be seen as a reddish glow. Corona (2,000,000 o C): is an even thinner layer of gas that surrounds the chromosphere. It is much hotter than the sun's surface at 2,000,000°C. Consists of the hotter gases that escaped surface.

6. Solar “Weather” Solar wind: a steady stream of ions and electrons from the sun, an extension of the corona. Strong solar winds can interrupt electronic signals on earth. Prominences: Large loops of gas that extend from the surface of the sun. Can stand up to 30 000 km high. Prominences are generally short-lived and fall to the surface again after only a few hours, but they can be held in position by the magnetic field for as long as several months. Sunspots: Cooler areas on the sun's surface where the magnetic field is especially strong. Solar flares with temperatures of up to 4 000 000 ° C can erupt and last anywhere from ten minutes to an hour. Solar flares can speed up the solar wind and cause a magnetic storm on earth.

8. Jupiter Earth 7 Our Sun

9. 1. Vital Statistics: A. Diameter – 865,000 miles B. Color – Yellow C. Apparent Magnitude - -26.5 D. Absolute Magnitude - +4.7 E. Period of Rotation – About 35 days at the poles and 25 days at the equator F. Earth = 1, Sun = 332,000 G. Surface Temperature – 12,000 degrees Fahrenheit Hot enough to melt any known substance H. Composition- 76 % Hydrogen, 22% Helium, and About 2 % heavy elements (Very similar to Gas Giants)

10. Sun’s Energy A. Suns’ Energy is generated by Nuclear Fusion - In the process Electromagnetic Energy (Visible light, UV light, X-rays, Gamma rays) is released. -In the core of the Sun, Hydrogen is being fused to make Helium This process is called Hydrogen “Burning”, but it is really fusing.

11. Hydrogen Fusion

12. A. Hydrostatic Equilibrium- Balance between the forces holding the Sun together (Gravity) and the Forces trying to rip the Sun Apart (Nuclear Fusion Explosions)

13. Below the surface of the sun (photosphere), density is proportional to temperature.

15. The atmosphere of the Sun -Chromosphere- - Pink glowing region of gas just above the photosphere - Can be seen by the naked eye only during a solar eclipse - Spicules- spikes of glowing gas probably due to magnetic changes 2. Corona – - Above Chromosphere – Temperature of about 2 million F - Layer of extremely hot ionized glowing transparent gas - Only visible during an eclipse or by viewing through a coronagraph (Machine that artificially eclipses the Sun) due to transparency of gas.

16. Star Life Cycle

17. 1st Step: –Stars form from nebulas Regions of concentrated dust and gas –Gas and dust begin to collide, contract and heat up All due to gravity

18. 2nd Step: –As nebula contracts, a small star is formed Called a protostar –Eventually, the protostar will begin nuclear fusion Hydrogen protons attract to each other –Strong nuclear force –Fusion begins Necessary for stars to survive

19. 3rd Step: –Star joins the main sequence 90% of star’s life is spent here Nuclear fusion = Hydrogen into Helium Mass of star determines location on main sequence

20. H-R Diagram

21. Beginning of the End: –Stars begin to die when they run out of accessible hydrogen Gravity begins to take over –Star begins to shrink; outer core of hydrogen begins to fuse Star grows bigger when it accesses outer core fuel

22. Beginning of the End: –When star gets bigger, it cools down Red giant –Eventually, star can fuse helium into other elements Carbon, oxygen, and other heavier elements

23. Beginning of the End: –Once star runs out of “fuel”, star shrinks under its own gravity –Turn into a white dwarf, neutron star, or black hole

24. Death of Stars: –What stars end up as depend on mass –Low and Medium mass stars Planetary nebula --------- white dwarf –High mass stars Supernova --------- neutron star or black hole

25. Death of Stars: Low Mass Brown Dwarf? Main Sequence Star Black Dwarf?

26. Death of Stars: Medium Mass Red Giant Main Sequence Star Planetary Nebula White Dwarf

27. As fusion begins to slow down, the core of the sun will contract Temperature in the core will rise The outer layers of the sun will expand, consuming in the inner planets A medium sized star will become a Red Giant

29. –Core of the sun will begin to fuse helium into larger elements such as carbon and oxygen –Continuing over the next 100 million years… Core will become entirely carbon and oxygen Core will contract Outer layers will expand –Outer layers will form a planetary nebula Core of sun will become a white dwarf

30. Death of Stars: High Mass Red Super Giant Main Sequence Star Supernova Neutron StarBlack Hole

31. High Mass Stars: –Mass greater than 8x our sun Create high mass elements such as iron –Neutron Star Formed if remaining star < 3x sun’s mass –Black Holes Formed if remaining star > 3x sun’s mass

32. Black Holes Info Sheet What is a Black Hole??? –An object so massive and dense that not even light can escape its gravity –The end result from a supernova of a star that has a mass greater than 3x the sun