What two observable properties of a Cepheid variable are directly related to one another?
A)its mass and its distance
B)the period between its peaks of brightness and its distance
C)the period between its peaks of brightness and its luminosity
D)its luminosity and its mass

Question

Quizplus · Accepted Answer

The period between the peaks of brightness (i.e. the pulsation period) of a Cepheid variable is directly related to its luminosity. This relationship was first discovered by Henrietta Leavitt in the early 1900s and is now known as the period-luminosity relation. Using this relationship, astronomers can use the pulsation period of a Cepheid variable to determine its intrinsic luminosity, and therefore its distance from Earth.

What Two Observable Properties of a Cepheid Variable Are Directly