The Crab Pulsar (PSR B0531+21) is a supernova remnant located in the Crab Nebula. The pulsar is roughly 10 kilometers in diameter and rotates once every 33 milliseconds, or 30 times each second, emitting x-rays as it does. The image shows x-ray emissions gathered by the Chandra X-ray Observatory in blue, and optical ones from the Hubble Space Telescope in red.