When enough gas has acummulated in a place and it starts collapsing, does the star “turn on” like a lightbulb or is it more like a slow process where it gets brighter and brighter for like, a hundred years until the fusion reaction is at full potential?
In: Planetary Science
Baby stars are actually quite bright long before they begin fusion, because they are heated by gravitational collapse. (It’s like what happens when you force CO2 into a cylinder: the cylinder will warm up. This is just at astronomical scales, so the heat is far, far greater.)
There won’t be any flash, and in fact the star may become *dimmer* as it switches from compression heating to fusion heating.
Latest Answers