In 1959 U.S. astronomer Stewart Sharpless published a catalog of 312 Hydrogen-ii emission nebulae. This is number 140, a large, faint region of ionized hydrogen gas nebulosity about 3,000 light years distant in the constellation Cepheus. At its heart is a cluster of three deeply embedded young stars that are obscured by the dark cloud of dust and gas in the lower-right.
| Exposure |
• 10¾ hours (65 X 10 minutes) @ -20°C ☞ 15 full color ☞ 50 with Hα filter • Dusk flats • Camera position angle: 193° |
| Processing |
• With PixInsight: ☞ Calibrate, star-align, integrate subframes ☞ TGVDenoise to reduce noise ☞ Histogram transformation • Final tweaking and sizing in Photoshop CS6 |
| Date and Location |
• October 10 & 11, 2022 • December 24, 2022 • Louisa County, Virginia, USA |
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Equipment |
• TMB-130SS APO refractor @ f/7 on an A-P 1200 mount • ZWO ASI-1600MC Pro color camera • Guided with a ZWO ASI-120M camera on a 60mm f/5 scope • Imaging and autoguiding with MaxIm DL 6.20 • Automated image acquisition with ACP Observatory Control |
Updated May 23, 2023