Celestial hemisphere:  Northern  ·  Constellation: Pegasus (Peg)  ·  Contains:  NGC 7241
NGC7241 - Occulting Companion, 



    
        

            Jason Guenzel
NGC7241 - Occulting Companion
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NGC7241 - Occulting Companion

NGC7241 - Occulting Companion, 



    
        

            Jason Guenzel
NGC7241 - Occulting Companion
Powered byPixInsight

NGC7241 - Occulting Companion

Acquisition details

Dates:
Oct. 9, 2017 ·  Oct. 10, 2017 ·  Oct. 15, 2017 ·  Oct. 16, 2017 ·  Oct. 17, 2017 ·  Oct. 18, 2017
Frames:
Blue: 20×240(1h 20′) (gain: 0.00) -20°C bin 1×1
Green: 20×240(1h 20′) (gain: 0.00) -20°C bin 1×1
Luminance: 128×180(6h 24′) (gain: 0.00) -20°C bin 1×1
Red: 20×240(1h 20′) (gain: 0.00) -20°C bin 1×1
Integration:
10h 24′
Darks:
50
Flats:
50
Bias:
256
Avg. Moon age:
24.32 days
Avg. Moon phase:
32.16%
Bortle Dark-Sky Scale:
5.00

Basic astrometry details

Astrometry.net job: 1792100

RA center: 22h15m42s.7

DEC center: +19°1427

Pixel scale: 0.526 arcsec/pixel

Orientation: 50.848 degrees

Field radius: 0.195 degrees

Resolution: 2082x1661

File size: 1.2 MB

Description

At a magnitude of +13.5 and less than 3 arc minutes across, this edge on spiral doesn't seem to be the most obvious target to image in the constellation of Pegasus. Close inspection of the field reveals some interesting details.

NGC7241 is the larger "target" galaxy in this image. Deeper exposure reveals the faint 16 magnitude companion edge-on spiral, UGC11964. Both of these galaxies are estimated to be 48-49mly distant. So, they appear to be true neighbors.

NGC7241 is not your typical edge-on spiral. One thing that stands out is the appearance of bright blue "balls" that are somewhat off center from the core. What we are seeing is a result of our unique angle of view. We not only see the galaxy edge-on, but we are viewing a stellar stream of a low mass companion that is actually occulting NGC7241. Astronomers were able to deduce this feature by analyzing the rotational properties of the galaxy and finding that this area was clearly "out of place". We are looking right down the axis of a dwarf galaxy that passed through the host galaxy and is now strung out in space directly toward us. In fact a fainter stream (only barely perceptible in my image) extends away from the plane of the galaxy toward the lower right in this view.

Once again, I went after an exceedingly tiny target and came away impressed what my scope could produce, but certainly yearning for a bit more capability. I cropped this to a FOV only roughly 18x15 arcminutes.

Comments

Revisions

  • Final
    NGC7241 - Occulting Companion, 



    
        

            Jason Guenzel
    Original
  • NGC7241 - Occulting Companion, 



    
        

            Jason Guenzel
    B

B

Description: Small "fixes"

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NGC7241 - Occulting Companion, 



    
        

            Jason Guenzel