What did Edwin Hubble study in the Andromeda Galaxy that proved it was an individual galaxy and not part of our own Milky Way?
A) Cepheid stars
B) Type I supernovae
C) globular clusters
D) red giant stars
E) RR Lyrae variables

Question

Quizplus · Accepted Answer

Edwin Hubble studied Cepheid stars in the Andromeda Galaxy and found that they had a much longer period of variability than those in the Milky Way, indicating that the galaxy was much further away than previously thought. This discovery provided crucial evidence that the Andromeda Galaxy was actually a separate galaxy from our own.

What Did Edwin Hubble Study in the Andromeda Galaxy That