Hemisphere:  Northern  ·  Constellation: Cancer (Cnc)  ·  Contains:  NGC 2672  ·  NGC 2673  ·  NGC 2677  ·  NGC2672  ·  NGC2673  ·  NGC2677
Getting plate-solving status, please wait...
Arp 167, 


            Gary Imm
Arp 167, 


            Gary Imm

Arp 167

Getting plate-solving status, please wait...
Arp 167, 


            Gary Imm
Arp 167, 


            Gary Imm

Arp 167

Imaging telescopes or lenses: Celestron EdgeHD 11

Imaging cameras: ZWO ASI 294 MM Pro

Mounts: Astro-Physics Mach1GTO

Guiding cameras: ZWO ASI 174 MM Mini

Software: Main Sequence Software Sequence Generator Pro  ·  Pixinsight  ·  Stark Labs PHD2 2.6.3

Filters: Astrodon Green 31mm Gen2 I-Series  ·  Astrodon Blue 31mm Gen2 I-Series  ·  Astrodon Lum 31mm Gen2 I-Series  ·  Astrodon Red 31mm Gen2 I-Series

Accessory: ZWO EFW 2″X7  ·  Celestron OAG  ·  MoonLite Focuser for EdgeHD 11

Dates:Feb. 19, 2021Feb. 20, 2021

Astrodon Blue 31mm Gen2 I-Series: 30x120" (gain: 120.00) -20C bin 2x2
Astrodon Green 31mm Gen2 I-Series: 30x120" (gain: 120.00) -20C bin 2x2
Astrodon Lum 31mm Gen2 I-Series: 60x120" (gain: 120.00) -20C bin 2x2
Astrodon Red 31mm Gen2 I-Series: 30x120" (gain: 120.00) -20C bin 2x2

Integration: 5.0 hours

Avg. Moon age: 7.58 days

Avg. Moon phase: 52.06%

Astrometry.net job: 4278019

RA center: 8h 49' 22"

DEC center: +19° 4' 25"

Pixel scale: 0.342 arcsec/pixel

Orientation: -0.334 degrees

Field radius: 0.215 degrees

Resolution: 3634x2682

Locations: Backyard (Mag 20.8 - Bortle 4.5), Onalaska, Texas, United States

Data source: Backyard


This object is a pair of elliptical galaxies located in the constellation of Cancer at a declination of +19 degrees. This object was classified by Dr. Arp into the category of Galaxies with Diffuse Counter-tails. The key question here is – are these galaxies interacting?

The data suggests not. NGC 2672, the large 12.7 magnitude galaxy on the right, is 200 million light years away. It spans 1.5 arc-minutes in our apparent view with a diameter of 90,000 of light years. NGC 2673, the smaller 14.4 magnitude galaxy on the left, is only about 170 million light years away, which is too far from NGC 2672 to be interacting with it. However, the distance information always has some range of uncertainty.

Visually, NGC 2673’s surrounding star sphere has been distorted, suggesting it is a companion of NGC 2672. The larger NGC 2672 is less distorted, but that is not surprising since large ellipticals are often unaffected by companion interaction.

I believe that these two are interacting even though the data suggests that they are too far apart. Perhaps that is just me wanting to see galaxies such as these interact - I am funny that way, almost like I am encouraging these two galaxies to get into a brawl. What do you think - are they interacting , or not? And if not, what is causing the distortion of NGC 2673?

Numerous background galaxies appear in the image, especially on the lower right side. These background galaxies are about 800 million light years away.