For finding the distance to M31, Hubble relied upon
A) Cepheid variables in its spiral arms.
B) planetary nebulae near its core.
C) RR Lyrae stars in its globular clusters.
D) Type I supernova in its core.
E) Type II supernova in its spiral arms.

Question

Quizplus · Accepted Answer

Hubble used Cepheid variables in the spiral arms of M31 (Andromeda Galaxy) to calculate its distance. Cepheid variables have a well-defined relationship between their luminosity and pulsation period, allowing astronomers to use them as standard candles for measuring astronomical distances.

For Finding the Distance to M31, Hubble Relied Upon