A seriously faint (mag 18, surface brightness 24/sq arcmin) Wolf-Rayet nebula in Norma.
It is easy enough in H-alpha, in which at 5 hrs we see a pretty clam-shell structure. In OIII, it is very difficult to see anything at all against the billions of milky way stars, but after 10 hours, we see a much smaller ring-like structure. We were unable to convince ourselves that there was any meaningful SII, which would fit with it being a WR rather than and SNR.
Here we've mapped H-alpha (from 2015) to orange, and OIII (from the last several nights) to teal-blue.
There are so many stars, and so bright compared with the nebula, that it was unfruitful trying to do anything with the stars other than leave them as-is.
Large version here (slightly cropped).
You can see the structure better in the single channel monochrome images. The
5 hrs of H-alpha is here, and the
10 hrs of OIII is here.
Aspen CG16M on 20inch PlaneWave on MI-750 mount. H-alpha 5 x 1hr subs. OIII 10 x 1hr subs. -30C. Moon averaging about 50% illuminated.
Although difficult, we think it is a very pretty example of a WR nebula, and worth trying to see the structure against the starry background.
Cheers,
MnT