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Orion East and OB1 Molecular Cloud Remnants



Scope: FSQ-106N at f/5, Location: DAA Observatory, Shelter Valley, CA, 1 and 4 January 2022,  Camera: ASI1600MM (Astronomik Gen 2  Ha LRGB Filters)

Exposure:  Ha - 18 x 4 min (gain-200 1x1), Lum - 80 x 4 min (gain-180 1x1) ,  RGB -20 x 3 min (gain-120 1x1) each RGB exposures.

Processing: Data Collection -  Sequence Generator Pro (as FITs).  Sub-frame calibration, Sub-frame  registration and integration (Average combine -  Winsorized Sigma Clipping) - PixInsight (WBPP).  Mure Denoise - PixInsight. Non-linear stretching, normalization and gradient removal - PixInsight.  Generation of starless nebulosity Ha and Lum images and RGB stars only image for later processing - Star XTerminator. Lum and Ha starless images were screen combined for a starless Luminance layer; Ha starless was  mapped to RGB starless by channel weight in pixel math for each RGB channel; the RGB / Ha starless color image was combined with the starless Luminance layer - PixInsight. RGB stars only image was screened to the finished starless color image - PixInsight.  Final finishing  - Affinity Photo.  Photometric LRGB calibration - PixInsight. Annotation - PixInsight, Aladin (Simbad and NED), and Affinity Photo. This image is a  Ha RGB mapped  image (weighted Ha into RGB channels) with RGB stars.  Image processed at 4656x3520 resolution. Final Image size is approximately  4642x3498.

North is up in this image.  This image shows the area just east of the Orion Nebula (which is to the right outside of this image field). This is just a small portion of the Orion OB1 Association which was surveyed in a 1998 study of molecular cloud remnants remaining after a star class O or B star birth (Katsuo Ogura and Koji Sugitani, 1998). These remnants exhibited "shock wave" type fronts to one side with tails on the opposite side - they were categorized in one of three categories (bright  rimmed HII emission remnant, cometary globule remnant, or simple reflection remnant). All  seven in this image are of the cometary globule remnant type. Interestingly, the study also found that  the heads mostly pointed to a roughly common center in the "Sword of Orion" region. There are a few dark nebulae identified in the TGU catalog in this image as well. These objects and some of the brighter stars are identified in the annotated imageHorizontal FOV is approximately 115 arc minutes. Full size image scale is 1.49 arcsec/pix.

Image center is approximately - Equatorial 2000: RA: 05h 42m 52s Dec: -0524'44"


All images and content remain the property of Jim Thommes - copyright 2003 - 2022

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