Because of the period-luminosity relation for Cepheids and RR Lyrae variable stars, astronomers are able to _____
A) determine the relationship between the period of pulses and luminosity
B) measure the mass of a star
C) calculate a star's diameter
D) determine the chemical composition of a Type I Cepheid
E) narrow their study to eclipsing binary stars only

Question

Quizplus · Accepted Answer

The period-luminosity relation for Cepheids and RR Lyrae stars allows astronomers to determine the relationship between the period of their brightness variations (pulses) and their intrinsic luminosity. This relationship is crucial for measuring distances in astronomy.

Because of the Period-Luminosity Relation for Cepheids and RR Lyrae