He was also able to identify some Cepheid variables that he could use as a to estimate the distance to the nebulae: proving they were far too distant to be part of the Milky Way.
He was also able to identify some Cepheid variables that he could use as a to estimate the distance to the nebulae. He found that the the Andromeda Nebula is 275,000 parsecs from the Sun, far too distant to be part of the Milky Way.