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| Cassiopeia A: The 320 year old remnant
               of a massive star that exploded. Located in the constellation
               Cassiopeia, it is 10 light years across and 10,000 light years
               from Earth. Caption: In August of 1999, NASA released an image of Cassiopeia A, a supernova remnant revealed in never-before-seen X-ray detail. The "Cas A" image, as it has come to be known, shows remarkable structure in the debris of a gigantic stellar explosion, as well as an enigmatic source in the center, which could be a rapidly spinning neutron star or black hole. The Chandra X-ray Observatory image of Cas A ushered in a new era of X-ray astronomy. This image was produced from the archives to celebrate the anniversary of Chandra’s first light. The low, medium, and higher X-ray energies of the Chandra data are shown as red, green, and blue respectively. Scale: Image is 6.9 x 8.2 arcmin Chandra X-ray Observatory ACIS Image 
                              
                  CXC operated for
                  NASA by the Smithsonian Astrophysical
                  Observatory
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