(Updated Dec. 2017) The Crescent Nebula in Cygnus is an emission nebula with interesting surface patterns and wisps of oxygen (in blue) around the shell. This is a much longer exposure than I had previously done on this target, and that plus extensive processing reveals some details not often seen in this nebula, such as the white cylindrical structures seen in the upper left portion of the Crescent. Scope: AT111EDT at f/5.7 Mount: AP Mach1 Camera: QSI 683 at –20C Exposure: 12 x 1800s H-a, 6 X 1800s O-3, 6 x 1800s S-2 (12 hrs total)