The region on the H-R diagram where pulsating variables occur is called the:
A)period-luminosity relation.
B)mass-luminosity relation.
C)instability strip.
D)horizontal branch.
E)main sequence appendix.

Question

Quizplus · Accepted Answer

The instability strip is the region on the H-R diagram where pulsating variables occur. Pulsating variables fall within a specific range on the H-R diagram known as the instability strip. This strip corresponds to a specific range of temperatures where the star's outer layers are unstable and undergo periodic expansions and contractions, leading to changes in luminosity. The period-luminosity and mass-luminosity relations are not specific regions on the H-R diagram, and the horizontal branch and main sequence appendix are not related to pulsating variables.

The Region on the H-R Diagram Where Pulsating Variables Occur