English: The Crab Nebula (Messier 1) is a well-known supernova remnant (the remains from massive star whose life ended in a massive explosion). This false-color image of the Crab Nebula was taken at the Vatican Observatory on Mount Graham using Sloan u’, g’, and r’ filters. The yellow filaments on the outside of the remnant are primarily ionized hydrogen gas and show up in both the u’ and r’ filters. The gas in the interior of the nebula is heated by the neutron star left by the explosion and its glowing light is visible in all the filters. While the neutron star itself is too faint to be see in the visible, the glowing disk of gas and debris that surround it also shows up quite clearly in the g’ filter (blue-white colors). One of the jets thrown off by the accreting neutron star is also partially visible in the g’ filter to the lower-left of the accretion disk.