Sharpless 266 is a nebula surrounding supergiant star MWC 137 (V1308 Ori, HIP 29988, TYC 1315-1508-1 and many others). The object was thought to be a planetary nebula at one time. The latest distance estimates put this one at 3558 light-years away in Orion.
Luminance – 24x600s – 240 minutes – binned 1x1
RGB – 8x300s – 40 minutes each – binned 2x2
360 minutes total exposure – 6 hours
Imaged February 3rd, 4th and 5th, 2018 from Dark Sky New Mexico at Rancho Hidalgo (Animas, New Mexico) with a SBIG STF-8300M on an Astro-Tech AT12RCT at f/8 2432mm.
LRGB - https://www.flickr.com/photos/dcrowson/40089952952/sizes/l
I ended up capturing 12 hours of Ha but, while the background has a lot of Ha, I didn’t feel it added much to the image so it was not used.