1. Mike Chris

3. Stars begin as a nebula, or clouds scattered dust made mostly of hydrogen As the nebula collapses the contents of it begin to to heat up. This is known as a protostar This phase can be referred to as the fetus of the star http://www.godandscience.org/images/nebula.jpg

4. Brown dwarfs are objects in space They are not technically stars, and are bigger than planets http://seanf.hypexr.org/project/Brown_Dwarf.jpg Brown Dwarf

5. The main sequence is where stars live most of their lives Right now, our sun is in the main sequence A star begins the main sequence when nuclear fusion begins http://www.noaanews.noaa.gov/stories2005/images/sun-soho011905-1919z.jpg Main Sequence Star

6. Nuclear fusion is when two atoms combine to make a larger one In stars this is between hydrogen and helium When a star runs out of hydrogen, it starts fusing helium and carbon Larger stars can fuse carbon into even heavier elements like iron

7. When a star starts burning helium, it starts to pack the atoms tighter together, causing the outside of the star to expand When this happens, it is classified as a red giant This is the first step into old age http://www.lancs.ac.uk/ug/hilditch/pic3.gif Red Giant

8. Planetary nebula is a nebula that has gas and plasma Planetary nebulas are made of dead stars After a red giant a planetary nebula is made http://en.wikipedia.org/wiki/File:NGC6543.jpg Planetary Nebula

9. The cores of low-mass stars are white dwarfs White dwarfs are close to the size of the Earth, but may weigh as much as our sun They are not as bright as larger stars White dwarfs are very bright because of the heat made when the star collapsed A black dwarf is made when white dwarf becomes cold Black have not been proven to exist because it takes longer for a white dwarf to become one than the universe has been in existence http://cactus.dixie.edu/smblack/chem1010/images/Unit_4/4A_white_dwarf_star.jpg White Dwarf

11. Massive main sequence stars are the same as small or medium-mass except that they are bigger so they burn hydrogen faster https://segue.atlas.uiuc.edu/uploads/ryemm2/blue%20main%20sequence.jpg Massive Main Sequence Star

12. Supergiants are the largest stars in our universe They can have a diameter of around 1,000 times bigger than our sun http://isc.astro.cornell.edu/~sloan/fun/figures/star_agb.gif Supergiant

13. A supernova is an explosion of a high-mass stars This happens when a star’s supply of energy and light runs out This only happens every few millions of years http://imagine.gsfc.nasa.gov/Images/bios/stecker/large.supernova.jpg Supernova Remnant E0102-72

14. A neutron star is the result of a supernova A neutron star is small and dense and is mostly made up of neutrons, hence the name A neutron star is bigger in mass than our sun http://nrumiano.free.fr/Images/Neutron_star_E.gif

15. A black hole is another result of a supernova It is a thing in space that has such a strong pull of gravity so strongly that light can’t be seen Until recently, astronomers didn’t know that black holes even existed because black holes can’t be seen with a telescope http://ucsdnews.ucsd.edu/graphics/images/2006/neutron-star-jet_bg.jpg Black Hole

16. High-mass and low-mass stars take different paths at the end of their lives High mass stars burn their fuel faster than low-mass stars, which is why low-mass star live much longer than high-mass stars Also, high mass stars end their lives with a supernova, then a black hole or a neutron star Low mass stars end their lives by becoming a white dwarf http://www.geosociety.org/graphics/04denver/blackhole.jpg Black Hole

17. Most massive-20 million years Our sun-10 billion years Least massive-1 trillion years http://www.keyway2.ca/jpg/stars.jpg