Sharpless 308 (RCW 11) is a faint nebula ionized by Wolf-Rayet (https://en.wikipedia.org/wiki/Wolf%E2%80%93Rayet_star) star WR 6 (EZ CMa and others) at the center of the image. The nebula appears to be located approximately 4,500 light-years away in Canis Major. I suspect that this object would have a fairly bright OIII component but at nearly -24 declination, it would be rough to collect the data needed from the northern hemisphere.
Luminance – 12x600s – 120 minutes – binned 1x1
RGB – 8x300s – 40 minutes each – binned 2x2
240 minutes total exposure – 4 hours
Imaged October 20th and 21st, 2017 from Dark Sky New Mexico at Rancho Hidalgo (Animas, New Mexico) with a SBIG ST-8300M on an Astro-Tech AT90EDT at f/6.7 603mm.
LRGB - https://www.flickr.com/photos/dcrowson/38233628606/sizes/l