In 1920, astronomers Harlow Shapley and Heber Curtis held a Great Debate. Shapley argued that the spiral nebulae were small and in the Milky Way, while Curtis took a more radical position that they ...

In commemoration of Edwin Hubble's discovery of a Cepheid variable class star, called V1, in the neighboring Andromeda galaxy 100 years ago, astronomers partnered with the American Association of ...

This is the largest photomosaic ever assembled from Hubble Space Telescope observations. It is a panoramic view of the neighboring Andromeda galaxy, located 2.5 million light-years away.

Edwin Hubble ... taking images of spiral nebulae every clear night and looking for the telltale variations of Cepheid variables. By the end of 1924, he had found 12 Cepheids in M31.

Edwin Hubble ... taking images of spiral nebulae every clear night and looking for the telltale variations of Cepheid variables. By the end of 1924, he had found 12 Cepheids in M31.

A hundred years ago, astronomer Edwin Hubble dramatically expanded the size ... Hubble worked hard, taking images of spiral nebulae every clear night and looking for the telltale variations of Cepheid ...