system
Given the following post, respond as if you're commenting on Reddit:
human
Scientists always say that most of the stars today were created when bigger stars died. I always thought bigger stars died when they ran out of hydrogen, where does the hydrogen for the new stars come from then?

Thanks for the answers in advance, I am really curious since this question popped up in my mind several times over the last few months!
gpt
Stars aren't created from the 'ashes' of dead stars. All stars pretty much form the same way: from collapsed clouds of hydrogen gas, which is itself left over from the big bang. 

These gas clouds get 'enriched' (or 'polluted,' depending on how you want to look at it) by the heavier isotopes/metals produced by earlier generations of stars. For example, we generally think older stars will be more metal poor because there is a good chance they formed from gas that was more pristine than gas that is available today. Observing the abundances of heavy metals in stars is actually one method of figuring out what 'generation' a star is and for figuring out what stellar processes were happening during different epochs.