Arp 145 / UGC 1840

Designation(s)Arp 145, UGC 1840
Object Type(s)Galaxy
Relevant Catalog(s)All (Chron), Arp
Arp CategoryMaterial emanating from elliptical galaxies
Obs. Lat/Long42° 17', 073° 57'
ConstellationAndromeda
Date and Time Observed2024-02-29 20:00:01
Instrument8" EdgeHD SCT
CameraASI294mc-Pro
Image DetailsRight is 94.3 degrees E of N. Total integration time was 24m30s. Exposures 30s@305g, darks subtracted, UV/IR Cut Filter, dithered and recentered in SharpCap. Darks subtracted, no flats. Dithered and recentered in SharpCap. No guiding. Featured image and comparison rotated 90° and enhanced in Affinity Photo from original SharpCap capture..
DescriptionReviewing this before submission to the AL in Feb 2025, a year after the original capture,, I feel the same about this target as I do Arp 141: this is as likely to be a merger as a showing "emanating material". As part of this "rethinking", I created the inverted monochrome image from my original OSC capture, which depicts things much more clearly in combination with the positive. The galactic center of the elliptical galaxy is obviously the large, medium-bright object just left of image center (the three stars in a line are lower in the image and point to it). All of the other bright objects are imo field stars, EXCEPT the medium bright object which forms the upper vertex of a triangle in combination with the two brightest field stars. If you look at my inverted image, it's the smallest of the three. If believe this could be the center of a spiral galaxy being absorbed into the Elliptical rather than emanating from it. This capture took place despite an 88% moon. I was determined to capture a number of Arp galaxies in Andromeda, recognizing the window of opportunity in Feb 2024 was short. This was the second observation of the evening, and the target was fairly low in the west. I captured as much data as I could until I judged the thicker atmosphere and glow at the horizon would render further integration useless.
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