What must occur for an object to be considered a main-sequence star?
A)Hydrostatic equilibrium ends.
B)Nuclear fusion reactions in the core begin.
C)Helium flash occurs in the core.
D)Gravitational contraction begins.

Question

Quizplus · Accepted Answer

Main-sequence stars are stars that are fusing hydrogen in their cores to produce energy. Therefore, for an object to be considered a main-sequence star, it must have nuclear fusion reactions in the core, which is option B.

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