With some spare imaging time left over on the previous two nights after Orion disappeared from view I had a crack at NGC 7822 which lies roughly halfway between the constellations Cassiopeia and Cepheus. Here's the result - south is down:
The nebulosity visible is entirely from the Hydrogen alpha emission line and the stars were added in from a separate set of RGB exposures.
This one had me scratching my head a bit when I saw the naked Hα image as I knew the ring couldn't be lens flare. Here was the puzzle: it's near the bottom of the image above, just to the right of centre and it looks like this (50% crop) with the stars turned down a bit:
It took me the best part of two hours to track this down and it's called Abell 85 (or CTB 1 if you prefer). There's a brief description of it here
The main subject NGC 7822 is worth closer inspection and you can read more about it here
5 x 1500 seconds Hα (Astrodon 3nm)
5 x 200 seconds in each of R, G and B (Astrodon Tru-Balance)
Lens: Pentax 6x7 MF 165mm at f/2.8
Target: 00h 05m, +67° 14'
Processed in PixInsight and PhotoShop