The farther up and to the left the turnoff point of a cluster of stars plotted on the H-R Diagram is,the
A) older the cluster is.
B) younger the cluster is.
C) farther away the cluster is.
D) closer the cluster is.

Question

Quizplus · Accepted Answer

The position of a star cluster's turnoff point on the Hertzsprung-Russell (H-R) Diagram indicates its age. A turnoff point farther up and to the left corresponds to hotter and more luminous stars, suggesting a younger age, as these stars have not yet evolved off the main sequence.

The Farther Up and to the Left the Turnoff Point