| A | B |
|---|
| nebulas | where stars begin their lives |
| mass | determines a stars lifetime |
| 10 million to 200 billion years | the length of time a star may live |
| gravity | the force that pulls together the matter in stars |
| longer | stars with less mass will have ___ lives |
| giant or supergiant star | the explosion of this causes a supernova when it runs out of fuel |
| white dwarf | a star that has no fuel but glows faintly |
| 40 times | black holes form from stars that have _______ the mass of the sun |
