NGC 6888 - Crescent and Soap Bubble

This area within the greater Sadr region in the constellation Cygnus contains the Crescent nebula - the product of the tremendous stellar winds of a Wolf-Rayet star.  These relatively rare stars are massive, young, and highly luminous.  Gasses cast off during formation of the star are overtaken by intense radiation and fast stellar winds causing a shock wave to form.  Here, hydrogen gas (red) is surrounded by an envelope of oxygen gas (blue).  Also seen in this area is the Soap Bubble, a recently discovered, nearly perfectly spherical faint outgassing from a dying star (above and left of center).