The glowing gas ring around Supernova 1987A

This NASA/ESA Hubble Space Telescope Wide Field and Planetary Camera 2 image shows the glowing gas ring around supernova 1987A, as seen on 2 February 2000. The gas, excited by light from the explosion, has been fading for a decade, but parts of it are now being heated by the collision of an invisible shockwave from the supernova explosion.