The period-luminosity relation is critical in finding distances with:
A)RR Lyrae stars.
B)trigonometric parallaxes.
C)spectroscopic parallaxes.
D)Cepheid variables.
E)pulsars.

Question

Quizplus · Accepted Answer

The period-luminosity relation is a relationship between the period of variability and the intrinsic brightness of Cepheid variables. By measuring the period of the Cepheid variable, astronomers can determine its intrinsic brightness and use this to calculate its distance from Earth using the inverse square law of light. Therefore, the period-luminosity relation is critical in finding distances with Cepheid variables. The period-luminosity relation is most commonly used with Cepheid variables to find distances.

The Period-Luminosity Relation Is Critical in Finding Distances With