M1, Crab Nebula

"Chinese astronomers noted the explosion leading to the Crab Nebula first on 4 July 1054. According to records, the bright source was visible during the daytime for 23 days."

The explosion of a star is called supernova. The star spews its innards out across the sky, creating an expanding wave of gas and dust known as a supernova nebula. One the most famous of these supernova remnants is M1, also called the Crab Nebula.

The Crab Nebula lies at a distance of 6,500 light years from Earth and is like our sun system part of the Perseus Arm of the Milky Way galaxy. The nebula has a total luminosity 75,000 times that of the Sun. Messier 1 is about 11 light years in diameter and keeps expanding at a rate of about 1,500 kilometres per second. In the middle of the nebula, a neutron star rotates at a rate of 30.2 times per second, also called a pulsar. This pulsar is the youngest one observed and emits radiation in optical, radio, ultraviolet, X-ray and gamma ray wavelengths.