Celestial hemisphere:  Northern  ·  Constellation: Serpens (Ser)  ·  Contains:  NGC 5951  ·  NGC 5953  ·  NGC 5954
Getting plate-solving status, please wait...
Arp 91 and NGC 5951, 



    
        

            Gary Imm
Arp 91 and NGC 5951, 



    
        

            Gary Imm

Arp 91 and NGC 5951

Getting plate-solving status, please wait...
Arp 91 and NGC 5951, 



    
        

            Gary Imm
Arp 91 and NGC 5951, 



    
        

            Gary Imm

Arp 91 and NGC 5951

Acquisition details

Dates:
March 26, 2021 ·  March 27, 2021
Frames:
Astrodon Gen2 I-Series Tru-Balance Blue: 30×120(1h) (gain: 120.00) -20°C bin 2×2
Astrodon Gen2 I-Series Tru-Balance Green: 30×120(1h) (gain: 120.00) -20°C bin 2×2
Astrodon Gen2 I-Series Tru-Balance Lum: 60×120(2h) (gain: 120.00) -20°C bin 2×2
Astrodon Gen2 I-Series Tru-Balance Red: 30×120(1h) (gain: 120.00) -20°C bin 2×2
Integration:
5h
Avg. Moon age:
12.76 days
Avg. Moon phase:
95.21%

RA center: 15h34m10s.843

DEC center: +15°0613.17

Pixel scale: 0.344 arcsec/pixel

Orientation: -0.176 degrees

Field radius: 0.217 degrees

More info:Open 

Resolution: 3600x2762

File size: 2.9 MB

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

Data source: Backyard

Description

This image captures multiple objects in the constellation of Serpens at a declination of +15 degrees.

Arp 91 is the object at upper left, comprised of a pair of interacting galaxies located 100 million light years away. This object was classified by Dr. Arp into the category of Spiral Galaxies with Large, High Surface Brightness Companions on Arms. NGC 5953 is the magnitude 13 galaxy on the right. Although this looks like an elliptical galaxy in my image, the Hubble image shows it to be a face-on lenticular spiral galaxy. It is about 50,000 light years in diameter. NGC 5954 is the magnitude 14 spiral galaxy on the left, 40,000 light years in diameter.

I suspected in my image, and confirmed in the Hubble image, that NGC 5953 lies in front of NGC 5954. The star stream that extends to the right from the bottom of NGC 5954 appears to stop abruptly, but that is because the dense core of NGC 5953 is obscuring it. It is interesting to me that NGC 5953 appears relatively undisturbed, yet NGC 5954 is fairly messed up. Arp considered NGC 5953 to be the “companion”, but it looks the other way around to me.

At bottom right is the grand design spiral galaxy NGC 5951, a bit closer at 80 million light years away. This magnitude 13 galaxy spans 3.5 arc-minutes in our apparent view, which corresponds to a diameter of 90,000 light years. We are looking at this galaxy less than 10 degrees from edge-on. A nice arm structure is present but it is difficult for us to see it. The disk is disturbed to some extent, but it is not clear why.

Finally, the small dim edge-on warped spiral galaxy below Arp 91 is UGC 9902. It is 25,000 light years in diameter. Like NGC 5951, this galaxy is also 80 million light years away, so perhaps they are interacting with each other.

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