Sharpless 274 (Abell 21, LBN 1051 and the Medusa nebula) is a planetary nebula located approximately 1050 light-years away in Gemini.
Ha – 30x1800s – 900 minutes – binned 1x1
OIII – 24x1800s – 720 minutes – binned 1x1
RGB – 8x300s – 40 minutes each – binned 2x2
1720 minutes total exposure – 29 hours
Imaged over 14 nights from February, 2016 through February, 2020 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.
HOO-RGB - https://www.flickr.com/photos/dcrowson/51075069997/sizes/l/
My previous LRGB image can be found here - https://www.flickr.com/photos/dcrowson/33534546662/sizes/l