As one moves upward and to the left on the H-R diagram, the stars become
A) cooler and redder.
B) hotter and redder.
C) cooler and bluer.
D) hotter and bluer.

Question

Quizplus · Accepted Answer

Moving upward on the H-R diagram indicates increasing luminosity, while moving to the left indicates increasing temperature. Stars that are hotter emit more blue light, making them appear bluer. Therefore, as one moves upward and to the left, the stars indeed become hotter and bluer.

As One Moves Upward and to the Left on the H-R