M82 (also known as NGC 3034, or the Cigar Galaxy) is a starburst galaxy in the Ursa Major constellation.
The Chandra X-ray Observatory detected fluctuating X-ray emissions from the sector, appoximately 600 light-years away from the centre of M82, around 12 million light-years from Earth. Astronomers have postulated that M82 would contain the first known mid-mass black hole, of roughly 500 solar masses.
See also: Messier 82, SEDS Messier pages