What important role do Cepheid variables stars have in astronomy?
A) distance measurements to galaxies
B) determination of stellar luminosities
C) determination of speeds of stars in galactic arms from the Doppler shift of their spectra
D) keeping of accurate time

Question

Quizplus · Accepted Answer

Cepheid variables serve as important standard candles for measuring astronomical distances. Their predictable brightness variations allow astronomers to determine the distance to galaxies in which they are observed.

What Important Role Do Cepheid Variables Stars Have in Astronomy