Great Andromeda Galaxy. Computer-coloured image of the Great Andromeda Galaxy (M31; NGC 224). It is located 2.2 million light years from Earth in the constellation Andromeda. At 200 light years across it is the largest galaxy in the inslocal groupins, the cluster of around 25 galaxies that includes our own, the Milky Way. Like the Milky Way, Andromeda is a spiral galaxy with a dense central bulge packed with millions of stars. Also on this image are two small companion galaxies near Andromeda: M32 or NGC 205 (at upper right) and M110 or NGC 221 (the small star-like object just below Andromeda's centre).