The Crescent nebula also known as NGC6888 is a cloud of hot gas in the constellation Cygnus. The gas was initially expelled by the Wolf Rayet Star WR136 when it was a red giant about 300.000 years ago. The gas is now heated by the intense radiaton and stellar wind from WR136 which is about 600.000 times brighter than the sun. The star is near the end of its life and will result in a supernova in the future.