IC 2169 is a fairly obscure (seldom imaged)
reflection nebula visually located in the constellation Monoceros. It is thought to be about 2,500 light years away from us, which would give it a semi-major axis of about 20 light years.
The entire field is about the angular size of a full moon. Technical Information: L:R:G:B: 555:195:180:240 (a total of almost 20 hours of light-frame exposure time); there are thirty-three 15-minute exposures and 20 3-minute exposures through the
luminance filter; red and green exposures were all 15-minute exposures; blue were all 20-minute exposures. The luminance layer consisted of an HDR blend of the 15-minute and 3-minute exposures. Equipment: RC Optical Systems 14.5 inch Ritchey-Chrétien carbon fiber truss telescope, with ion-milled optics and RCOS field flattener, at about f/9, and an SBIG STX-16803 camera with
internal filter wheel (SBIG filter set), guided by an SBIG AO-X, all riding on a Bisque Paramount ME German Equatorial Mount. Image Acquisition/Camera Control: Maxim DL, controlled with ACP Expert/Scheduler, working in concert with TheSky X. Processing: All images calibrated (darks, bias and sky flats), aligned, combined and cropped in Pixinsight. Color combine in Pixinsight. Some finish work (background neutralization,
color calibration, NoiseXTerminator and BlurXTerminator) done in Pixinsight; some cleanup finish work was done in Photoshop 2024. Location: Data acquired remotely from Sierra Remote Observatories, Auberry, California, USA. Date: Images taken on many nights in November and December of 2024. Image posted May 24, 2025. Date: Image scale of full-resolution image: 0.56 arcseconds per pixel. Seeing: Generally good. CCD Chip temperature: -25C Copyright 2024, 2025
Mark de Regt