The little Cepheid that stopped
Friday, January 14, 2011 - 10:30
in Astronomy & Space
When Hubble first discovered a Cepheid variable in the galaxy M31, the universe grew. Previously, many astronomers had held that the fuzzy spiral nebulae were small patches of gas and dust within our own galaxy, but through the Period-Luminosity relationship which allowed him to determine the distance, Hubble demonstrated that these were island universes, or galaxies in their own right.