Sure sounds simple - gas and dust collect under gravity and when enough pressure is built up you have a star. But here’s what I don’t get. Say you’ve got a planet such as Jupiter in the middle of a dust cloud. Over eons it gains dust and gas. At some point fusion would occur. At this exact moment, wouldn’t the outward pressure from the fusion prevent the star from keeping this reaction going? Before the star lit up, there was just barely enough pressure to start fusion, so it seems to me that as soon as it starts the star should go out. The shock wave should blow some material off the star so it shouldn’t restart either. Not until it collects more matter and then the cycle should repeat. Seems like it should only be able to light and stay lit if a lot of material was added to it at one time.
One other question. I’ve read that once a star begins to make iron that it only has a few seconds to live. How? Being that the inner planets are full of iron, wouldn’t that stand to reason that the sun already has some too? And wouldn’t this iron be at the center? I realize iron does not emit energy as it fuses to new materials (either that or no energy is made from fusing elements into iron). But the sun should be able to keep fusion going around the iron. I’d think that fusion would only stop once iron filled the entire area being used for fusion.