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 Ia supernovae
C) Globular clusters
D) Red Giant stars

Question

Quizplus · Accepted Answer

Edwin Hubble studied Cepheid variable stars in the Andromeda Galaxy and found that they were much farther away than any stars in our own Milky Way. This observation led him to conclude that the Andromeda Galaxy was a separate galaxy and not part of the Milky Way.

What Did Edwin Hubble Study in the Andromeda Galaxy That