Supernova - Space.com explains supernova, super nova,
supernovas, supernovas in space and supernova remnants
Chandra - Field Guide to X-ray Sources - Supernovas & Supernova
Remnants - An explanation of cosmic X-ray sources, from black holes
to galaxy clusters, as well as a review of the history of X-ray
astronomy, what X-rays are and how they are produced
