I imaged NGC 2655 3 years ago using the CCD FLI 16803 and Pixinsight's PhotometricColorCalibration...

https://www.astrobin.com/sa3bk0/

With a new paper on the formation of this galaxy just published this month, I decided to image again using the CMOS ASI6200MM Pro and a more traditional ColorCalibration that omits the strong red shift typically seen with PhotometricColorCalibration.

https://phys.org/news/2023-01-kinematics-gas-galaxy-ngc.html

When I compare my CCD image from 3 years ago to this new CMOS image, I was very surprised to see how much detail the old 16803 sensor uncovered. The overall integration time is about the same, so I suppose the seeing conditions 3 years ago may have been better than they were this year. Nevertheless, the old 16803 is certainly a keeper with its larger sensor compared to the 6200.

During January, the seeing in Julian @ 4,200' is not great. Data for this image was collected from January 21 through the 27th as I worked around high winds and very poor seeing (4"+) during most of those days. 

In the end, I was able to collect...

71 5-minute L subs between 1.9" and 2.7"
26 5-minute B subs between 3" and 4.2"
30 5-minute G subs between 2.8" and 3.8"
30 5-minute R subs between 2.3" and 3.8"


"At a distance of about 79.5 million light years, NGC 2655 is a giant disk galaxy in the constellation Camelopardalis. The diameter of the disk of NGC 2655 is approximately 195,000 light years, while the mass of the galaxy's stellar population is estimated to be 200 billion solar masses.

NGC 2655 is the brightest member of the NGC 2655 group, which includes seven galaxies brighter than −15 mag, and all of them are of the late type. This suggests that the whole gas content of NGC 2655 could result from accumulating the surrounding dwarfs by the central galaxy.

NGC 2655 has two exponential disks. These disks have different scale lengths and also different orientations of the isophote major axis. The internal and external rotation axes of the stellar disk of NGC 2655 are inclined to each other. NGC 2655 is a multi-spin galaxy.

The orientations of the huge disk of neutral hydrogen and the outer stellar disk in NGC 2655 coincide with each other both spatially and kinematically. The outer gaseous disk lies within the outer stellar disk, and that even current star formation is taking place somewhere in it.

A minor merger took place in NGC 2655. A small satellite galaxy struck the central part of NGC 2655 almost vertically about 10 million years ago."