The higher the luminosity (intrinsic brightness) a Cepheid variable is,
A) the smaller its mass
B) the lower it is on the main sequence of the H-R diagram
C) the longer the period of its variations
D) the closer it is to us
E) the larger the telescope we need to observe it

Question

Quizplus · Accepted Answer

The period of a Cepheid variable is directly related to its luminosity, with brighter Cepheids having longer periods. This relationship, known as the period-luminosity relation, allows astronomers to use Cepheids as standard candles to determine distances to other galaxies.

The Higher the Luminosity (Intrinsic Brightness) a Cepheid Variable Is