The Crab pulsar is a neutron star that is at the heart of the Crab Nebula. The Crab Nebula’s filaments and structure may become apparent in 16-inch telescopes under good conditions, while smaller telescopes, starting with 4-inch aperture, only reveal some detail in the shape of the remnant. 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.
The Crab Pulsar is 16th magnitude and can only be seen in larger telescopes (20 inches or so) in very good viewing conditions, with clear skies and no light pollution. Some pulsars, such as the Crab and Vela pulsars, are losing rotational energy so precipitously that they also emit radiation of shorter wavelength. Discovered in 1968, the pulsar was the first to be connected with a supernova remnant. The Crab Pulsar (PSR B0531+21) is a relatively young neutron star. In pulsar: Pulsars in visible light, X-rays, and gamma rays.
It is a relatively young pulsar, the Supernova was first observed on Earth by Chinese astronomers on July 4th, 1054 A.D. and was visible during the day for 23 days and at night for almost two years. The Crab Pulsar appears in optical photographs as a moderately bright (magnitude 16) star in the centre of the Crab Nebula.