A star enters the main sequence when _________________.
A) nuclear fuel in its core can supply enough energy to stop its collapse
B) it collapses, and its envelope becomes degenerate
C) it stops fusing nuclear fuel in its core and starts to expand
D) it forms planets

Question

Quizplus · Accepted Answer

A star enters the main sequence when nuclear fusion in its core generates enough energy to counterbalance gravitational collapse, achieving hydrostatic equilibrium.

A Star Enters the Main Sequence When _________________