Stephen D Pastor
A Takahashi CCA250 f/5 astrograph with a QSI683wsg camera @ -20 degrees C. (Astrodon Gen 2 filters) on a Paramount ME on the nights of 23, 30 Nov and 5 Dec 2016 and 13, 18, 19 Jan 2018 in Mayhill, NM (Lum 30 x 1200 sec; Red 5 x 1200 sec; Green 5 x 1200 sec; Blue 5 x 1200 sec; with corresponding Flats, Darks, and Bias). Processed in PixInsight 184.108.40.2063 Ripley (x64). Color calibration and RGB image stretch with PixInsight’s Photometric Color Calibration and Arcsinh Stretch, respectively.
Open cluster NGC 1931 surrounded by emission and reflection nebulosity Sharpless 2-237 is in the constellation Auriga. Faint red hydrogen emission can be see in the region surrounding the compact cluster/nebulosity. Sharpless 2-237 shows both red hydrogen emission and blue reflection nebulosity. Image was a total of 15 hours of exposure.