CTB 1 supernova remnant, composite image. This supernova remnant is the remains of a massive star that exploded. It is around 100 light years across, and 10,000 light years distant, in the constellation of Cassiopeia. Here, it has been observed at radio wavelengths (orange, yellow and green), together with infrared observations (blue). The radio observations were made with the Very Large Array (VLA) and the Canadian Galactic Plane Survey. At centre left is the straight, glowing trail from pulsar J0002+6216. Image published in 2019.