S Andromedae

S Andromedae, also known as SN 1885 (Supernova 1885), is the only supernova seen to date in the Andromeda Galaxy and the first supernova observed beyond the galaxy in which we live, Milky Way Galaxy. S Andromedae (a variable star designation) was discovered on Aug. 19, 1885, by the Irish amateur astronomer Isaac Ward in Belfast, and independently the following day by Ernst Hartwig (1851–1923) at Dorpat Observatory in Estonia; Hartwig was the first to realize its significance.


S Andromedae reached magnitude 6 between Aug. 17 and 20, and had faded to magnitude 16 by February 1890. In 1988, R. A. Fesen and colleagues using the 4-meter Mayall telescope at Kitt Peak discovered the remnant of the explosion; further observations were made with the Hubble Space Telescope in 1995.