Why are Cepheid variables important?
A)Cepheid variables are stars that vary in brightness because they harbor a black hole.
B)Cepheids are pulsating variable stars,and their pulsation periods are directly related to their true luminosities.Hence,we can use Cepheids as "standard candles" for distance measurements.
C)Cepheids are a type of young galaxy that helps us understand how galaxies form.
D)Cepheids are supermassive stars that are on the verge of becoming supernovae and therefore allow us to choose candidates to watch if we hope to observe a supernova in the near future.

Question

Quizplus · Accepted Answer

Cepheids are pulsating variable stars, and their pulsation periods are directly related to their true luminosities. This property allows astronomers to use Cepheids as "standard candles" to measure distances to other galaxies. This technique is crucial in determining distances of galaxies beyond the Milky Way and has been instrumental in determining the size and age of the universe.

Why Are Cepheid Variables Important