Two stars have the same spectral classification,but it is observed that one of them has narrower spectral lines than the other.The star with the narrower spectral lines is:
A) hotter.
B) cooler.
C) more luminous.
D) less luminous.

Question

Quizplus · Accepted Answer

The star with narrower spectral lines is likely more luminous because it has a lower surface gravity, which causes less pressure broadening of the spectral lines. This is typical of larger, more luminous stars.

Two Stars Have the Same Spectral Classification,but It Is Observed