What must occur for an object to be considered a main-sequence star?
A) hydrostatic equilibrium
B) nuclear fusion reaction in the core
C) protostar life begins
D) both a and b

Question

Quizplus · Accepted Answer

For an object to be considered a main-sequence star, it must be in a state of hydrostatic equilibrium, meaning the inward gravitational force is balanced by the outward pressure force generated by nuclear fusion reactions in the core. Therefore, both option A (hydrostatic equilibrium) and option B (nuclear fusion reaction in the core) must occur for an object to be considered a main-sequence star.

What Must Occur for an Object to Be Considered a Main-Sequence