NGC6888, Cresent Nebula, Cygnus, Stellarvue SV78S f6, MX7C, 60min

NGC 6888, which is named the Crescent Nebula, was formed by the collision of the stellar wind of the 7th magnitude Wolf-Rayet Star star HD 192163 (the bright star near the center of the image) with material shed during its preceding phase as red supergiant star. Wolf-Rayet stars are incredibly hot (25,000-50,000 K) and expel their outer layers of gas at high velocities (thousands of kilometers per hour). The resulting nebula is a bubble enveloped in a skin of emission nebula which is shock-heated by the collision. It measures 26 x 16 light years and is located in the Cygnus Arm of our Galaxy.