Sh2-155 “The Cave Nebula”

The Cave Nebula lies in the constellation Cepheus about 2,400 light years away, pretty close in cosmic terms.  The “cave” has a bright rim ionized by the hot blue-white stars in the vicinity. The main “cave” structure is 10 light years across and is catalogued as Sharpless 155 (Sh2-155) and also as Caldwell 9 (the Caldwell catalogue was compiled by Sir Patrick Moore, and named for his mother’s maiden name). Near the lower left corner of the image is a blue reflection nebula, vdB 155. The Cave Nebula region makes a nice natural colour image, highlighting red emission nebula, blue reflection nebulae, dark nebulae and many colourful stars. I’ve also imaged the Cave Nebula before at higher resolution; that image was publishedin the April 2016 issue of Sky and Telescope.

Tekkies:
Acquisition, focusing, and control of Paramount MXmount, with TheSkyX. Focus with Optec DirectSync motor and controller. Unguided. Automation with CCDCommander. Equipment control with PrimaLuce Labs Eagle 3 Pro computer. All pre-processing and processing in PixInsight. Acquired from my SkyShed in Guelph. Average transparency and seeing. Data acquired March 2-14, 2021 in a mostly moonless sky.

Sky-Watcher Esprit 150 f/7 refractor and QHY 16200-Acamera with Optolong H-alpha, O(III) and S(II) filters

Ha: 49 x 10m = 8hr10m
O3: 47 x 10m = 7hr50m
S2: 45 x 10m = 7hr30m

Total: 23hr30m

Copyright: Ron Brecher