Sharpless 91
Starless
Image Details:
The Sharpless 91 region is located in the Southern edge of Cygnus, a cross-shaped constellation seen high in the sky during the Northern Hemisphere’s Summer. This supernova remnant is close in proximity to the Veil Nebula (also located in Cygnus) and is even sometimes referred to as the “Little Veil,” despite being about the same apparent size. However, this shell of luminous matter is located on the other side of the Milky Way’s bright column (which can be seen as the glow on the right side of the photo) and is likely much older than the event which created the Veil Nebula. The brighter background of the nearby Milky Way make this a difficult object to capture, necessitating use of both high contrast narrowband filters (3nm, for the most part) and travel to Bortle 1 skies (skies lacking light pollution) for capturing true broadband color.
Equipment:
William Optics Star71-II Petzval APO (345mm Focal Length, F/4.9)
ZWO ASI6200MM-P, ZWO Filters
Hypertuned Celestron CGEM-II
Autoguiding: Orion 50mm Guidescope + ZWO ASI224MC
Exposures:
Red, Green, Blue: 75, 74, 72 x 180” (Total: 11h 3m)
Hydrogen-Alpha 3 nm: 195 x 300” (Total: 16h 15m)
Hydrogen-Beta 7 nm: 96 x 300” (Total: 8h)
Oxygen-III 3 nm: 156 x 300” (Total: 13h)
Misc Details:
Capture Software: AstrophotographyTool, PHD2 (guiding), Celestron CPWI (mount control), Pegasus Powerbox (dew heater control, power management)
Processing Software: PixInsight
Taken from: Wichita, KS, Bortle 5 & OkieTex Star Party, OK, Bortle 1
Capture Dates: 18-19, 24-25 June, 9 July, 10, 14-15, 18-21 August, 8 September, 2023