called the Andromeda Nebula (after the constellation in which it was located). It was entry 31 in Charles Messier's 18th century catalog of interesting fuzzy objects, and is thus also called M31 ...

A Michigan State University researcher saw X-rays coming from a black hole using the NASA Chandra X-Ray Observatory telescope ...

The Andromeda galaxy is surrounded by a constellation of dwarf galaxies that are arranged in a highly lopsided manner. Analysis of cosmological simulations published in Nature Astronomy reveal that ...