Sh2-73 (Hercules) , May 2023
Televue 127is telescope and A-P Mach2 mount
ASI6200MM Camera, Baader BB CMOS Opt Filters
Lum (89 x 360s exposures, Bin 1x1 Gain 0)
RGB (3 x 40 x 120s exposures, Bin 1x1 Gain 100)
Total Integration Time = 12.9 hours

The Sharpless catalog, published in two editions was an attempt at a comprehensive listing of the hydrogen emitting regions - at least north of -27 degrees azimuth. There are 313 such regions in the catalogue, but a few are not true H2 emitting regions, but rather, are planetary nebula or supernovae remnants - but still contain hydrogen spectral emissions.
Sh2-73, however, is a true imposter, in that it doesn't have any hydrogen emissions to speak of. It is simply, a molecular cloud - it does contain hydrogen, but also molecules of heavier elements.
Hydrogen emissions are dominated by a red colour and result from adsorption of (generally UV) radiation and reemission in the visible spectrum. In contrast, Sh2-73 simply reflects back the accumulated light given off by the Milky Way.
A big hint is its location, above the plane of the galaxy where it can reflect light from the galactic disc/plane. At this time of year, the galactic disc, where the rest of the Sharpless catalogue mainly reside, is too low in the sky to be imaged.
I have to admit, it is likely one of the least spectacular of the Sharpless images, and even it's inclusion in the catalog was a mistake. It is very dim though, and I was happy to get it, despite our non-ideal skies.