What causes a star to burn? What causes a star to burn out?

Hydrogen and helium are the initial elements required for nuclear fission. When stars start to run out, they move on to heavier elements such as carbon. In this sense, every element in the universe is a byproduct of an exploding star.

	bobbonew -  2656 pts -  (3 years ago)
	We are all elements of star dust! But in all seriousness I have tried to understand the concept of fusion and how a star can actually burn for millions of years without burning out. I guess we have to think of it as something completely different to fuel and that it doesn't just get used up.

	angel82992 -  96 pts -  (3 years ago)
	Well they do burn out. But their lifetimes are in the order of billions of years, much longer than the human race has been around.

Well, first, Stars do not "burn". They are hot, but burning is just oxidation.

angel82992 is right, but to add to that; When stars die when they run out of fuel, when this happens the inside has less gravitational pull and the extreme forces pushing outward win over. This generally cause the star to nova or simply expand into being a giant to take care of as much fuel as possible before such a time as it then novas or collapses in on itself.

This can create dwarfs or, if big enough, black holes.

My favorite are Neutron stars because they aren't quite dense enough to be black holes, but all of the electrons are forced into the nuclei of the elements left in the star causing the charge to be completely neutral. This material is still incredibly dense, but I don't think it can even become a black hole.


I think it would be interesting to add a small amount of this material to the center of a moon and see what happens, or attempt nuclear fission upon it.