Why Are RR Lyrae Variables NOT Used to Find Distances

Why are RR Lyrae variables NOT used to find distances to distant galaxies?

A) RR Lyrae variables are found in globular clusters. They are not found in other galaxies.
B) The periods of RR Lyrae variables are irregular and thus not reliable for distance measurements.
C) They are not bright enough to be seen at large distances.
D) By their nature, RR Lyrae variables are surrounded by clouds of gas and dust. The resulting extinction makes their luminosities difficult to determine.

Correct Answer:

Verified

Unlock this answer now
Get Access to more Verified Answers free of charge

Access For Free