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Home Q & A Board Science-Related Homework Help Physics
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tqwolfork tqwolfork
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10 years ago
What is the source of energy in a collapsing protostar? At what point does that protostar become a main sequence star? What events signals the end of the main sequence life of a star?
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10 years ago
Whole books are dedicated to these questions but in a nutshell:

Gravity causes the star to collapse.  Gas pressure causes heat and the pressure and temperature increase (for a suitably sized star) until such time as Hydrogen Fusion begins.  Once the star has reached equilibrium it enters the main sequence.

Once the hydrogen fuel source in the core depletes the star leaves the main sequence and stars climbing the giant branch on the HR diagram for the first time.
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dbassandbassan
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10 years ago
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