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Are most of the starrs that we can see dead?
No they are alive and well, thank you. That means they still have material inside them, like hydrogen, that is being consumed by nuclear fusion and turned into heavier elements. This process releases a lot of energy that heats up the star to incandescence. At the end when all of the fuel is burned they can either just get dimmer and dimmer or, in special cases, go out with a huge bang. This spectacular event is called a supernova. The old decrepit stars are called brown dwarfs.
See: http://en.wikipedia.org/wiki/Supernova for more information
(published on 07/21/09)
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