720 XTF Search Results (expand=subject;f1-spectral-Type=X-ray;f2-subject=Crab Nebula);f1-spectral-Type%3DX-ray;f2-subject%3DCrab%20Nebula Results for your query: expand=subject;f1-spectral-Type=X-ray;f2-subject=Crab Nebula Thu, 01 Jan 1970 12:00:00 GMT X-ray Crab Nebula. The Crab Nebula, some 6,000 light years from Earth, is the remnant of a supernova explosion. It was seen on Earth in the year 1054. At the center of the bright nebula is a rapidly spinning neutron star, or pulsar, that emits pulses of radiation 30 times a second. This view shows the Crab in the X-ray wavelength. Sun, 29 Aug 1999 12:00:00 GMT