What's the deal with supernova's and nebulas?

Question

If I recall correctly, I was told as a student that large stars eventually burn up all thier hydrogen fuel, forge a few of the hevier elements, and then burst into a super-nova, generating a cloud of other hevier elements.

Supposedly, this cloud becomes a nebula, and new stars and planetary systems form from it.

So here's my problem: where is all the hydrogen coming from the create these new stars? Supposedly the old star ran out of the stuff.

This implies that either the new stars are drastically, collosally smaller, or that there is some fission process going on, of which I was not previously aware.

So what's going on here?

Answer 1

They make up everything we know including other stars. They have to meet up with it's perfect match to make anything it creates. It will not just be another star, it could be after a long time and all of the other matter and materials are meet up together. So the stars and other planets can be smaller or even get bigger. This all takes time and precision. This just doesn't happen over night.

Answer 2

Wow! At last, a truly intelligent question on Yahoo Answers :)

The hydrogen you ask about is already present in the nebulae where new star/planet formation may occur. Hydrogen is easily the most abundant element in the universe. A supernova seeds the nebulae with the heavier elements and provides the shock waves that can initiate new star and planet formation.

Answer 3

The remnant gases of small dead stars sometimes forms luminous nebulae around it, that in the past were though to generate planets and so they were wrongly named planetary nebulae. The name remains but today we know that planets or star are not born here.
Giant molecular clouds, contractions of the interstellar medium, do evolve with time into protostars, and the remainder material after the star is born forms protoplanets.

Answer 4

In addition to Braxton's correct answer, I would add that my interpretation of your question suggests that you think that a star fuses 100% of it's hydrogen before it dies. That is not so. The star's fuel is the hydrogen in its core. The hydrogen in the outer layers may never make it down to the core to participate in the fusion process. As a result, when a supernova takes place, an hefty percentage of the star's outer atmosphere, still raw hydrogen, is flung out into space.

Answer 5

For a star to super-nova it has to be big to begin with or have mass dumped on it to get big (binary star system). As it spews out all of that matter (including unfused hydrogen), it colides with other matter (generally hydrogen and space dust). Now, imagine millions and millions of stars doing this over time. Think popcorn on a very large scale. Hydrogen is the most plentiful thing in our spacetime universe.

Answer 6

The universe has bucket loads of hydrogen in it, the waste material from an exploding star triggers it to accumulate.

Also there will be fission involved in the explosion converting heavy elements back to hydrogen