Date Posted: 1/24/2024
Date Taken (RGB): 1/13/2016, 2/5/2016, 2/11/2016, 2/27/2016, 2/29/2016
Date Taken (Lum): 1/11/2024, 1/17/2024
Scope: Planewave CDK 12.5 f/8, 2541mm
Camera: SBIG STL-11000 with Astrodon Tru-Balance E-Series Gen2 filters
Temp: -15C
Mount: Losmandy Titan
Guiding (RGB): SSAG, Celestron 80mm guide scope, 600mm.
Guiding (Lum): On-axis via ONAG-XM and SX UltraStar at 2541mm. FocusLock real-time focus for focusing.
Exposure: LRGB 315:170:175:165 Luminance 15min unbinned; RGB 5min binned 2x2.

Calibrated and Stacked with CCDStack2; RGB combine and DDP with MaximDL. Processed with CS4.

From right to left the galaxies in this image are NGC 3169, NGC 3166, and NGC 3165. NGC 3169 and 3166 are locked in a death spiral, and doomed to ultimately merge. They are estimated to be only about 160 thousand light years apart. NGC 3169's outer arms are gradually being pulled away, making it look somewhat like an unraveling ball of yarn or cotton candy. The trio are located about 65 million light years away in Sextans, and are part of the Leo II Group of galaxies.

I originally shot this in 2016, with only so-so transparency on two of the 4 nights. In 2024 I re-shot the luminance, and combined the re-processed luminance it with the original RGB from 2016. Better transparency and seeing, along with improved processing, led to a deeper, much-improved image. I retained the original 2016 image in the Galaxies album for comparison.