Gum 15 (BRAN 176, RCW 32 and others) is the dark red HII nebulous region on the right side of the image. The rest of the clouds (including Gum 15) are part of SFO 57 and 58 (http://articles.adsabs.harvard.edu/pdf/1994ApJS...92..163S). Gum 15 and the associated clouds are located approximately 3,000 light-years away in Vela.
RGB – 40:36:40x600s – 400:360:400 minutes each – binned 1x1
1160 minutes total exposure – 19 hours 20 minutes
Imaged over thirteen nights from November 23rd and December 7th, 2019 at the El Sauce Observatory (Rio Hurtado, Chile) with a FLI PL 9000 on a PlaneWave CDK24 at f/6.5 3974 mm.
This is a Telescope Live (https://telescope.live/) “Pro Data Set.”
RGB - https://www.flickr.com/photos/dcrowson/51121832739/sizes/l/