A remnant light years away in one of the Milky Way's galactic neighbours. This image shows ambient gas being shocked by the expanding blast wave from the exploding star. Photograph: J Hughes (Rutgers University) and Heritage team/CXC/SAO/Nasa/ESA
This image is NGC 6543 known as the Cat's Eye Nebula as it appears to the Chandra X-Ray Observatory and Hubble Telescope. A planetary nebula is a phase of stellar evolution that the sun should experience several billion years from now, when i.