This is a really good beginning, anyway I want to know more. I have a problem with the "death" of stars, I know somethings about their final process, they begin to burn a different material, and then I don't know anything else. The next passage that I know is the explosion, Supernova or Red Giant, and now I sure that is only a question of mass...
The following basics may assist your learning....
1) All stars form from about 75% hydrogen and 25% helium. This is the stuff that came from the Big Bang. The expansion rate ~ 13.8 billion years ago caused primal matter to only form those two atoms, plus a tiny amount of lithium and a few other elements.
So, all stars consist of about that same proportion of hydrogen and helium. [I am ignoring how stars produce the other elements.]
Stars spend most their life in what is known the Main Sequence and understanding what happens during this period serves better to understand the other periods. So what happens....
1) Stars come from clouds, really big ones. Thousands of stars can emerge from a cloud that has gone through its phase of collapsing into thousands, sometimes hundreds of thousands, of regions.
2) Each collapse will have its own amount of mass that forms the central body.
3) If the mass formed exceeds about 1% that of the Sun's mass, the core density and temperature that has steadily gotten hotter and hotter during formation, will smoothly, IIRC, transition to fusing hydrogen. [Deuterium and lithium will likely fuse earlier but this is a story for protostars and pre-mainsequence stars, not main sequence stars that are in an equilibrium state.]
4) A very low mass star will take fuse hydrogen slowly. They are small and very dim. They use up their hydrogen and they're done.
Red dwarfs....Guaranteed to be a low mass star, some can be less than ~ 1% the mass of the Sun. Being a lightweight, it will last for perhaps a trillion years. So none have expired naturally. [I guess that’s a pun.
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5) More collapsed mass means the core will be more dense and it will have a higher temperature. Fusion will be far more productive. They are bigger and brighter.
As these more massive protostars form, their centers get hotter and hotter, much more so than the little red dwarfs. Eventually, the core conditions, as always, collapse to the point they will allow a smooth transition to hydrogen fusion.
But stars, like our Sun, have enough mass that as the hydrogen fuses to helium, the core itself will contract. Eventually, this shrinkage will have higher and higher temperatures and other conditions that will reach a point that helium fusion takes place.
But, surrounding this helium burning core is what? Hydrogen, right? So circumstances cab be that the inner core is fusing helium while the outer core is fusing hydrogen. I think that's true, eventually, for Sun-mass stars. [I know its true for the more massive ones.]
6) The really massive stars also go through this same process, but their greater mass causes a much faster rate of fusion. This makes them bigger and brighter.
These massive stars will slip off the Main Sequence, far sooner than the less massive stars, as they have layers of fusion, the top layer being hydrogen. They will continue to shrink as they consume their fuel until the point where the next element to burn is iron. When you fuse iron it absorbs energy. So if the star is massive enough to reach this point, the core will collapse as it fuses more and more iron, absorbing more and more energy, cooling the core, which triggers a super fast collapse. This triggers a supernova (Type II).
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