Gas ring around supernova 1987a. False-colour Hubble Space Telescope (HST) optical image of a ring of gas (yellow) around the remnants of supernova 1987a. This image was taken by the European Space Agency's Faint Object Camera on August 23rd, 1990. The tightly knotted debris from the stellar explosion appears as the red blob in the centre of the gas ring. The blue stars to the left & right of the ring are not associated with the supernova. The gas ring, some 170,000 light years from Earth, is eventually expected to be disintegrated by expanding debris from the supernova.