C27 Crescent Nebula – my best astrophoto yet!
The Crescent Nebula is an emission nebula in the constellation Cygnus, about 5000 light-years away from Earth and about 25 light-years wide. It is formed by the fast stellar wind from the Wolf-Rayet star WR 136, right in the center of the nebula, colliding with and energizing the slower moving wind ejected by the star when it became a red giant around 250,000 to 400,000 years ago. The result of the collision is a shell and two shock waves, one moving outward and one moving inward. The inward moving shock wave heats the stellar wind to X-ray-emitting temperatures.
To get this image I used my ED80 scope with my modded Canon 500D from my backyard. I used my new IDAS LPS-D1 light pollution filter which made a big difference with skyglow, allowing longer exposures. I stayed up until 3:30 am taking 50 separate 180 second unguided exposures, automated with BackyardEOS, for a total integration time of 2.5 hours. I also used 40 flats, 40 darks and 52 bias frames, stacking them all in Deep Sky Stacker, then doing image processing in Star Tools.
The resulting image is by far my best so far.