What event will eventually move an average star off the main sequence of the H-R diagram?
A)running out of hydrogen,causing gravitational influx,resulting in core temperatures high enough to begin fusing helium
B)surface cooling due to hydrogen loss
C)solar wind storms
D)its drift through space due to the gravitational attraction of neighboring giant stars

Question

Quizplus · Accepted Answer

As a star runs out of hydrogen in its core, there is no longer enough energy to counteract the inward pull of gravity, causing the core to contract and temperatures to increase. Eventually, the core temperature becomes hot enough to begin fusing helium, and the outer layers of the star expand and cool, moving the star off the main sequence of the H-R diagram.

What Event Will Eventually Move an Average Star Off the Main