Here's the conclusion of my week-long project to gather deep data for the Crescent Nebula in the excellent Julian, CA skies. Here I saw 21.3+ SQM with FWHM on 5-min subs between 1" and 2" for 6 days.
I particularly focused on OIII to help expose more of the faint nebulosity I've seen in other postings.
RGB was screened over the top for a deep and colorful star field.
"The Crescent Nebula (also known as NGC 6888, Caldwell 27, Sharpless 105) is an emission nebula in the constellation Cygnus, about 5,000 light-years away from Earth. It was discovered by William Herschel in 1792. It is formed by the fast stellar wind from the Wolf-Rayet star WR 136 (HD 192163) 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".
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