The Crab Nebula is a remnant of an exploded star. This is the Crab Nebula in various energy bands, including a hard X-ray image from the HEFT data taken during its 2005 observation run. Each image is 6′ wide. Credit: NASA.
Taurus XR-1 was discovered on April 29, 1963 at J1950 Right ascension (RA) 05h 31.5m Declination (Dec) +22°. An Aerobee sounding rocket carried a proportional counter fabricated by a team from the US Naval Research Laboratory. This experiment was the first to detect X-rays from the Crab Nebula supernova remnant (SNR).
SN 1054 is the supernova that produced the Crab Nebula. Because of its steady production of X-rays, the Crab X-ray source is often used as an X-ray emission standard.
