M1, or the Crab Nebula, is the remains of an enourmous explosion which occured in 1054. Since then the gas and dust thrown off in the explosion has been expanding out in a giant shell-like structure. The remnant of the exploded star is known as a pulsar, a very dense compact star spinning many times a second.

In the ultra-violet part of the electromagnetic spectrum the Crab is slightly smaller than it appears optically due to the higher energies required to produce the photons. Here, the central disk surrounding the pulsar can be made out, as well as more diffuse material in the surrounding nebula.

Image credit: Hennessy et al., UIT