The Crab Pulsar is a relatively young neutron star. The star is the central star in the Crab Nebula, a remnant of the supernova SN 1054, which was widely observed on Earth in the year 1054. Discovered in 1968, the pulsar was the first to be connected with a supernova remnant.
The Crab Nebula, which contains the Crab Pulsar (the red star in the center). Image combines optical data from Hubble (in red) and X-ray images from Chandra (in blue). Credit: NASA/CXC/ASU/J. Hester et al.
The sky seen in gamma-rays as seen by the Fermi Gamma-ray Space Telescope, reveals the Crab Pulsar as one of the brightest gamma-ray sources in the sky.
X-ray picture of Crab Nebula, taken by Chandra
A neutron star is a collapsed core of a massive supergiant star. The stars that later collapse into neutron stars have a total mass of between 10 and 25 solar masses (M☉), possibly more if the star was especially rich in elements heavier than hydrogen and helium. Except for black holes, neutron stars are the smallest and densest known class of stellar objects. Neutron stars have a radius on the order of 10 kilometers (6 mi) and a mass of about 1.4 M☉. They result from the supernova explosion of a massive star, combined with gravitational collapse, that compresses the core past white dwarf star density to that of atomic nuclei.
Central neutron star at the heart of the Crab Nebula
Radiation from the rapidly spinning pulsar PSR B1509-58 makes nearby gas emit X-rays (gold) and illuminates the rest of the nebula, here seen in infrared (blue and red).
A computer simulation depicting a neutron star with accretion disk, spewing out X-rays through the magnetic axis
NASA artist's conception of a "starquake", or "stellar quake"