False-colour radio map of the Crab Nebula (M1, NGC 1952) at a wavelength of 11 centimetres, taken with the Cambridge 5 km Telescope. The Crab Nebula is a supernova remnant about 6000 light years away in the constellation of Taurus. It is the remnant of a catastrophic stellar explosion which was observed by Chinese and Japanese astronomers in 1054 AD. At its centre is the Crab pulsar, a rapidly spinning neutron star which is the tiny, dense remnant of the star which exploded. The pulsar is only 10 km in radius & rotates 30 times each second. The map shows emission from electrons spiralling in the pulsar's strong magnetic fields.