Cassiopeia A

Cassiopeia A in X-Ray wavelengths.

Cassiopeia A in visible light.

One of the youngest known supernova remnants in the Milky Way, produced by the explosive death of a massive star.

Cassiopeia A acts as a natural particle accelerator, firing out cosmic rays. As particles move around the remnant, they're accelerated by the tremendous magnetic fields, eventually nearing the speed of light.