Andromedas Core . ... Credit Copyright: Robert Gendler Explanation: The center of the Andromeda galaxy is beautiful but strange. Andromeda , indexed as M31, is so close to our own Milky Way Galaxy that it gives a unique perspective into galaxy composition by allowing us to see into its core. Billions of stars swarm around a center that has two nuclei and likely houses a supermassive black hole over 5 million times the mass of our Sun . ... NASA Web Site Statements, Warnings, and Disclaimers . ...