The Crab Nebula (catalogue designations M1, NGC 1952, Taurus A) is a supernova remnant and pulsar wind nebula in the constellation of Taurus. It corresponds to a bright supernova recorded by Chinese and Arab astronomers in 1054. At X-ray and gamma-ray energies above 30 KeV, the Crab is generally the strongest persistent source in the sky. Located at a distance of about 6,500 light-years (2 kpc) from Earth, the nebula has a diameter of 11 ly (3.4 pc) and expands at a rate of about 1,500 kilometers per second. The nebula was the first astronomical object identified with a historical supernova explosion. The nebula is also referred to as Messier 1 or M1, being the first Messier Object catalogued in 1758.