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LBN 749, Barnard 3, and LDN 1468




Scope: FSQ-106N at f/5, Location: DAA Observatory, Shelter Valley, CA,   11 November 2020  Camera: ASI1600M (Astronomik Gen 2   LRGB Filters)

Exposure:  30 x 7 min (1x1 bin, gain 179) Luminance exposures, 16 x 4 min (1x1 bin, gain 79) each - RGB exposures.

Processing: Data Collection - Sequence Generator Pro (as FITs). Sub frame calibration - Pixinsight. Sub frame registration and integration (Average combine - Winsorized Sigma Clipping) - PixInsight. MURE Denoise - PixInsight.  Non-linear stretching, normalization and gradient removal - PixInsight.  Generation of starless nebulosity images (Luminance) - starnet++.  RGB combine, Luminance layering - PixInsight. Stars and Starless Luminance combine - PixInsight. Final finishing - Affinity Photo. RGB photometric calibration - PixInsight.  Annotation - PixInsight, Aladin (Simbad and NED), and Affinity Photo.  The monochrome starless was combined with a full monochrome image (one stop down in stretch) to minimize star bloat with pixel math. Images processed at 4656 x 3520 resolution. Final Image size is approximately 3022x4012.

North is up in this image. This field encompasses most of the LBN 749 structure - a large nebula from Lynds catalog.  By the colors, it looks to have dust and reflection as well as emission . It is given as an HII  emission region in Simbad. It is in the faintest LBN class 6. There are multiple embedded dark nebulae - LDN 1468, Barnard 3, and other darks (from Dobashi, TGU, and PGCC). Toward the left center is a small nebula GN 03.39.8 (DG  There are a few background galaxies  visible in this image in the upper right. They range from 111 to 612 million light years  distant (by redshift estimate).  These objects and some of the brighter stars are identified in the annotated image.   Vertical FOV is about 115'.  Full size image scale is  about 1.72 arcsec/pix. 

Image center is approximately - Equatorial 2000: RA: 03h 39m 55s Dec: +31 53' 58" 


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