Messier 46 (M46 or NGC 2437) is a bright open cluster approximately 5,500 light-years away in Puppis.
NGC 2438 is the planetary nebula right above M46. It is located approximately, 3,000 light-years away. It is illuminated by an estimated 17.7 magnitude central star.
Luminance – 12x600s – 120 minutes – binned 1x1
RGB – 8x300s – 40 minutes each – binned 2x2
240 minutes total exposure – 4 hours
Imaged March 12th, 13th, 24th and 25th, 2016 from 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/25773657790/sizes/l
See my refractor image here - https://www.flickr.com/photos/dcrowson/16657216397/sizes/l.