
Cassiopeia A. A supernova remnant about 11,000 light from Earth.
Cataloging the Stellar Graveyard
Supernovas are among the brightest phenomena in the universe, briefly outshining whole galaxies before they fade. The relatively short duration of these explosions means the best information about them frequently comes from their remnants, which are among the brightest sources of X-rays and gamma rays in the sky.
For that reason, astronomers have used the Chandra X-ray telescope to observe supernova remnants in the Milky Way and nearby galaxies. The Chandra Supernova Remnant Catalog is designed to bring the data from all the remnants observed using Chandra into a single place for comparison purposes. The catalog includes the spectrum of X-ray emission and the remnant morphology, which reveals the patterns of matter emitting the light within the clouds. The morphology of the remnants in turn provides important clues to the original supernova explosions, information that is difficult to obtain other ways.