1. By Zachary and Alba

2. Slides 3 through 12 is the life of a small to medium star. This is a picture of a red giant star.

3. Nebula: The first step in a stars life.  Nebula is a big cloud of gas & dust where stars form. This is a picture of the horse head nebula.  A nebula is considered the birthplace for stars.

4.  This is a picture of the Helix nebula.

5. Protostar  A protostar is a gaseous cloud of dust, gas and atoms.  Protostars either devolop into a Main Sequence star or a Small Protostar. This is a picture of the pillars of gas in the eagle nebula.

6. Small Protostars  A small protostar is a brown dwarf star.  This star is to small to create enough heat to start fusion.  Since it can’t start fusion it doesn’t shine brightly, so brown dwarf stars are very hard to see in the night sky. These are pictures of a brown dwarf right next to another bigger star.

7. Main Sequence  In a main sequence star the protostar gains enough mass to begin fusion.  The protostar could gain mass from clouds it goes through and other smaller protostars.  All Main Sequence stars fuse hydrogen.  A main sequence star will be a red giant when the Main Sequence runs out of hydrogen.

8. Hydrogen fusion  Hydrogen fusion is when 4 hydrogen nuclei come together to make helium nuclei.  The fusion cycle releases energy inside the core of the sun.  This fusion cycle generates the energy for our sun in our universe.

9. Red Giant  A Red Giant is a Main sequence star that has ran out of hydrogen and begins to fuse helium. When this runs out of fuel, it will turn into a Planetary Nebula. This is a picture of a red giant star.

10. Helium fusion  A kind of nuclear fusion.  Helium fusion is also known as the tri- alpha process.

11. Planetary Nebula  A Planetary Nebula is a red giant that completely stops fusing.  Since the star isn’t producing a pressure outward, the outer layers of the star are driven away.  A Planetary Nebula will turn into a White Dwarf.

12. White Dwarf  A White Dwarf star is a left over core from a star  A White Dwarf may only be the size of the Earth, but it has the mass of half of the sun.  Our sun will become a white dwarf after it runs out of fuel.  White dwarf stars are one of the densest forms of matter.

13. OR

14. Black Dwarf  A Black Dwarf is a White Dwarf that cools off over trillions of years until it no longer emits light.  There are no know Black Dwarf stars in the galaxy. Even if there were any we would not be able to see them because they are black. This is a picture of a black dwarf against a star filled back round.

15. Slides 16 through 23 are slides of big stars.

16. Nebula  A nebula for a big star is the exact same as for small to medium stars.  A nebula is a massive cloud of dust and different gasses.

17. Protostar  A protostar for a massive star is the same as a small to medium star.  A protostar is a small star that will turn into a massive main sequence star. This Is a picture of a protostar in the Eagle Nebula.

18. Massive main sequence star  Massive Main Sequence stars fuse hydrogen much faster than small or medium stars.  Since it fuses faster it runs out fuel so fast that it will turn into a Red Supergiant very quickly. This is a picture of a massive main sequence stars layers.

19. Red Supergaint  Massive main sequence star that runs out of hydrogen and begins fusing helium, then carbon, then oxygen etc.  A Red Supergiant star will turn into a Supernova when it runs out of elements that it can fuse.  A Red Supergiant will only live in this phase for a hundred thousand to a million years. This may semm like a long time to us, but it is no time at all in a stars life.

20. Supernova  Fusion stops in the star. Since the star isn’t fusing, gravity takes over and the star collapses.  When the star collapses, there is a gigantic exlposion that rocks the universe. This is a picture of 2 red supergiant stars colliding and producing a very big supernova.

21. Neutron Star  A neutron Star has a super dense core of a star that was left over after the explosion of a supern o v a.  A neutron star is only 10 to 15 miles in diameter; but have the mass of 1.5-2 times that of the Sun. This is a picture of a neutron.

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23. Black hole  Stars that have masses of 25 to 50 times that of the sun form black holes after a supernova.  The left over core of the star is so dense that is causes gravity to collapse. This is a picture of a black hole.

24. Websites Used!!!!!!!  http://www.historyoftheuniverse.com http://www.historyoftheuniverse.com  http://filter.case.edu/sjr16/advanced/star s_nebula.html http://filter.case.edu/sjr16/advanced/star s_nebula.html  http://en.wikipedia.org/wiki/helix_nebula http://en.wikipedia.org/wiki/helix_nebula  http://www.windows.ecar.edu http://www.windows.ecar.edu http://www.daviddarling.info/encyclopedi a/B/blackdwarf.html

25. More Websites  www.astrophysicsspectator.com/.../stars /MainSequence.html  en.wikipedia.org/wiki/Main_sequence http://www.sciencedaily.com/articles/r/re d_supergiant.htm http://aspire.cosmicray.org/labs/star_life/ starlife_proto.html http://en.wikipedia.org/wiki/Brown_dwarf

26. Other resources  Mr. Wildeboar’s slide show’s  Our notes