... UIT , NASA Explanation: This is the mess that is left when a star explodes. ... In the center of the Crab Nebula lies the powerful Crab pulsar - a spinning neutron star with mass comparable to our Sun but with the diameter of only a small town . ... The Crab still presents mysteries today as the total mass of the nebula and pulsar appears much less than the mass of the original pre-supernova star! ... Publications with keywords: pulsar - Crab Nebula . ... Crab Pulsar Wind Nebula . ...