Crab Nebula (image) University of Copenhagen Share Print E-Mail Caption The Crab nebula is the result of a type II supernova explosion observed by Chinese astronomers in 1054. The nebula consists of the outer parts of a red supergiant that exploded after having burned all its fuel. The nebula is still expanding into the surrounding interstellar medium with velocities of several thousand kilometers per second. In the middle of the nebula there is a neutron star, which is the collapsed central, dead core of the exploded star. Credit Hubble Space Telescope Usage Restrictions Credit: Hubble Space Telescope Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.