Hemisphere:  Northern  ·  Constellation: Cassiopeia (Cas)
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CTB1 - Abell 85, 



    
        

            Luca Marinelli
Powered byPixInsight

CTB1 - Abell 85

Getting plate-solving status, please wait...
CTB1 - Abell 85, 



    
        

            Luca Marinelli
Powered byPixInsight

CTB1 - Abell 85

Acquisition details

Dates:
Oct. 1, 2020 ·  Oct. 5, 2020 ·  Oct. 10, 2020 ·  Oct. 20, 2020 ·  Oct. 31, 2020
Frames:
Astrodon Narrowband 3nm Ha: 260×360(26h) (gain: 139.00) -15°C bin 1×1
Astrodon Narrowband 3nm OIII: 245×360(24h 30′) (gain: 139.00) -15°C bin 1×1
Astrodon Tru-Balance Gen2 E-Series - B 36mm: 30×60(30′) (gain: 50.00) -15°C bin 1×1
Astrodon Tru-Balance Gen2 E-Series - G 36mm: 30×60(30′) (gain: 50.00) bin 1×1
Astrodon Tru-Balance Gen2 E-Series - R 36mm: 30×60(30′) (gain: 50.00) bin 1×1
Integration:
52h
Darks:
50
Flats:
20
Flat darks:
50
Bias:
100
Avg. Moon age:
14.78 days
Avg. Moon phase:
70.46%
Bortle Dark-Sky Scale:
5.00

RA center: 23h59m48s.613

DEC center: +62°2708.15

Pixel scale: 0.685 arcsec/pixel

Orientation: 179.524 degrees

Field radius: 0.535 degrees

More info:Open 

Resolution: 4526x3342

File size: 10.2 MB

Locations: Home Observatory, Schenectady, New York, United States

Data source: Backyard

Description

CTB 1 (Abell 85, SNR G116.9+0.1) is a faint supernova remnant in the constellation Cassiopeia. It was originally cataloged by George Abell as a planetary nebula as Abell 85 but was identified by van der Bergh, Marscher and Terzian in 1972 as a supernova remnant based on its appearance in the optical as an almost perfect half-circle of radiative filaments. CTB 1 is approximately 10,000 light years away and physically spans roughly 100 light years in diameter. It is dated to be ~7,500-11,000 years old. (Hailey and Craig, Astrophys. J. 434:635, 1994).

The brightest arcs of the hydrogen shell can barely be seen in a single exposure with my optical train, while the OIII signal is significantly fainter. This image was the result of one of the first datasets collected in my brand new backyard roll-off roof observatory. The ability to squeeze every minute of clear sky was crucial to generate quality data for this faint deep-sky object.

The acquisition is primarily bi-color narrowband (Ha and OIII) and star color is replaced from RGB data. Calibration, stacking, and linear processing of the data in Pixinsight, star separation with Starnet (PI plugin). Non-linear processing in Photoshop CC with denoising using Topaz Denoise AI.

Comments

Revisions

    CTB1 - Abell 85, 



    
        

            Luca Marinelli
    Original
    CTB1 - Abell 85, 



    
        

            Luca Marinelli
    B
  • Final
    CTB1 - Abell 85, 



    
        

            Luca Marinelli
    C
    CTB1 - Abell 85, 



    
        

            Luca Marinelli
    D
    CTB1 - Abell 85, 



    
        

            Luca Marinelli
    E

B

Description: Slight curves adjustment.

Uploaded: ...

C

Description: Shrunk stars slightly to emphasize nebula.

Uploaded: ...

D

Description: Progressive buildup of signal to noise ratio as a function of number of subs used in the image integration process, from 1 to 292 subs in a small crop of the Ha channel.

Uploaded: ...

E

Description: Noise measured as the standard deviation of the signal in a small window of pure background sky as a function of number of subs in image integration. The square root dependence on number of subs is apparent.

Uploaded: ...

Sky plot

Sky plot

Histogram

CTB1 - Abell 85, 



    
        

            Luca Marinelli