Supernova Remnant
The structure resulting from the explosion of a star in a supernova. It consists of ejected material expanding from the explosion and the shocked interstellar medium it sweeps up.
Source: apod.nasa.gov
APODs including "Supernova Remnant"
Cas A: Optical and X-ray
17/01/2013
The aftermath of a cosmic cataclysm, supernova remnant Cassiopeia A (Cas A) is a comfortable 11,000 light-years away. Light from the Cas A supernova, the death explosion of a massive star, first reached Earth just 330 years ago. Still expanding, the explosion's debris cloud spans about 15 light-years near the center of this composite image. The scene combines color data of the starry field and fainter filaments of material at optical energies with image data from the orbiting NuSTAR X-ray telescope. Mapped to false colors, the X-ray data in blue hues trace the fragmented outer boundary of the expanding shock wave, glowing at energies up to 10,000 times the energy of the optical photons.