Celestial hemisphere:  Northern  ·  Constellation: Coma Berenices (Com)  ·  Contains:  NGC 4712  ·  NGC 4725
Getting plate-solving status, please wait...
NGC 4725 with Ancient Tidal Stream, 



    
        

            KuriousGeorge
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NGC 4725 with Ancient Tidal Stream

Getting plate-solving status, please wait...
NGC 4725 with Ancient Tidal Stream, 



    
        

            KuriousGeorge
Powered byPixInsight

NGC 4725 with Ancient Tidal Stream

Acquisition details

Dates:
June 1, 2019 ·  June 2, 2019 ·  June 3, 2019 ·  June 4, 2019
Frames:
Astrodon 50 mm G: 4×900(1h) -30°C bin 1×1
Astrodon 50mm B: 12×900(3h) -30°C bin 1×1
Astrodon 50mm L: 18×900(4h 30′) -30°C bin 1×1
Astrodon 50mm R: 10×900(2h 30′) -30°C bin 1×1
Integration:
11h
Darks:
20
Flats:
80
Flat darks:
80
Bias:
20
Avg. Moon age:
14.33 days
Avg. Moon phase:
1.72%
Bortle Dark-Sky Scale:
1.00
Mean SQM:
21.70

RA center: 12h50m22s.852

DEC center: +25°2917.74

Pixel scale: 0.468 arcsec/pixel

Orientation: 0.791 degrees

Field radius: 0.306 degrees

WCS transformation: thin plate spline

More info:Open 

Resolution: 3819x2740

File size: 2.0 MB

Locations: KG Observatory, Julian, CA, United States

Data source: Backyard

Description

My first version of this galaxy pair was taken during a short 4 hour clearing with 5-min luminance subs at -20C...

First version, 3.4 hours integration

Now with skies clearing and a marine layer yielding 21.7+ SQM skies, I had a chance to revisit with longer 15-min subs at -30C. I was hoping to expose the very faint tidal stream that Mark Hanson found using a CDK24 at the Stellar Winds Observatory in Animas, New Mexico. His inverted image (inset) is LRGB at 5.75. 3.25, 3.25 and 3.5 hours respectively.

On a good quality monitor with the brightess turned up, you can see this very faint tidal stream in my slightly shorter exposure. I suspect Mark has an even darker sky with greater transparency. I'm shooting at 4,200' with 80% humidity. He's at 4,406'with likely much lower humidity.

The glow on the left side is from a very bright star that didn't quite make it into the frame.

As always, I look forward to your comments!

Comments

Revisions

    NGC 4725 with Ancient Tidal Stream, 



    
        

            KuriousGeorge
    Original
    NGC 4725 with Ancient Tidal Stream, 



    
        

            KuriousGeorge
    B
  • Final
    NGC 4725 with Ancient Tidal Stream, 



    
        

            KuriousGeorge
    C

B

Description: Slight color desaturation.

Uploaded: ...

C

Description: De-noised background a bit more and removed insert.

Uploaded: ...

Sky plot

Sky plot

Histogram

NGC 4725 with Ancient Tidal Stream, 



    
        

            KuriousGeorge