Which group of stars in the H-R diagram would be labeled "zero-age main sequence"?
A)stars that have just collapsed from the interstellar medium
B)stars that are just beginning to convert helium into carbon in their cores
C)stars that contain no processed elements (elements heavier than hydrogen or helium)
D)stars that have just started converting hydrogen to helium in their cores

Question

Quizplus · Accepted Answer

Zero-age main sequence refers to stars that have just started converting hydrogen to helium in their cores. These are young, hot stars that are actively fusing hydrogen and are located along a diagonal line in the H-R diagram.

Which Group of Stars in the H-R Diagram Would Be