What was the implication of the observation by Edwin Hubble that the Cepheid variable stars he measured in the Andromeda "nebula" appeared to be very faint compared with what was expected?
A) The observed period was affected by the intense gravitational field of the "nebula" as predicted by general relativity, leading to incorrect luminosity determination.
B) The Andromeda "nebula" was very far away and was in fact a galaxy.
C) Hubble had discovered a new class of intrinsically faint Cepheid variable stars.
D) Dust and gas in the "nebula" had severely reduced the light from these stars.

Question

Quizplus · Accepted Answer

Edwin Hubble's discovery that the Cepheid variable stars in the Andromeda "nebula" were much fainter than expected led him to conclude that the "nebula" was actually a separate galaxy located at a tremendous distance from our own Milky Way. This observation helped provide evidence for the expanding universe and supported the idea that the universe was much larger than previously believed.

What Was the Implication of the Observation by Edwin Hubble