Over time,the turnoff point (the upper end of the remaining main sequence)of a cluster of stars plotted on the H-R Diagram moves
A) down and to the right.
B) down and to the left.
C) up and to the right.
D) up and to the left.

Question

Quizplus · Accepted Answer

The turnoff point of a cluster of stars represents the point where the most massive stars have exhausted their nuclear fuel and have left the main sequence. Therefore, as the cluster ages and more massive stars evolve off the main sequence, the turnoff point will shift to the lower left on the H-R diagram, indicating cooler and less luminous stars. Additionally, as the cluster ages, its stars will have exhausted some of their nuclear fuel, causing them to become cooler and less luminous, which also contributes to the shift of the turnoff point down and to the right on the H-R diagram.

Over Time,the Turnoff Point (The Upper End of the Remaining