- #1
dykuma
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Homework Statement
Why are stars hot?
Homework Equations
Non specifically, it's a conceptual question.
The Attempt at a Solution
I have always heard that stars are hot because (as a quick very basic example) stars are large collections of mass which collapse in on itself. Eventually the individual protons of this mass are able to tunnel past the Coulomb barrier and engage in fusion. Because of the mass defect, some mass is lost during fusion as energy, and this energy is what generates most of the heat of a star.
With that being said, I recall during a lecture in my astrophysics class that fusion can actually be thought of as a cooling process for the star. If it is not fusion that makes the star hot, then what is it? (this is not to say what I wrote above is wrong, but rather I am looking for a different way to view what produces the heat in a star.)