Celestial hemisphere:  Northern  ·  Constellation: Gemini (Gem)  ·  Contains:  PK205+14.1  ·  Sh2-274

Image of the day 03/13/2023

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    Closeup of Abell 21 (The Medusa Nebula) in SHO, 



    
        

            Bruce Donzanti
    Powered byPixInsight

    Closeup of Abell 21 (The Medusa Nebula) in SHO

    Image of the day 03/13/2023

    Getting plate-solving status, please wait...
      Closeup of Abell 21 (The Medusa Nebula) in SHO, 



    
        

            Bruce Donzanti
      Powered byPixInsight

      Closeup of Abell 21 (The Medusa Nebula) in SHO

      Acquisition details

      Dates:
      Feb. 19, 2023 ·  Feb. 20, 2023 ·  Feb. 22, 2023 ·  Feb. 25, 2023 ·  Feb. 26, 2023 ·  Feb. 27, 2023
      Frames:
      Chroma Blue 2": 10×60(10′) (gain: 100.00) f/10 -10°C bin 1×1
      Chroma Green 2": 10×60(10′) (gain: 100.00) f/10 -10°C bin 1×1
      Chroma H-alpha 5nm Bandpass 2": 49×600(8h 10′) (gain: 100.00) f/10 -10°C bin 1×1
      Chroma OIII 3nm Bandpass 2": 35×600(5h 50′) (gain: 100.00) f/10 -10°C bin 1×1
      Chroma Red 2": 10×60(10′) (gain: 100.00) f/10 -10°C bin 1×1
      Chroma SII 3nm Bandpass 2": 41×600(6h 50′) (gain: 100.00) f/10 -10°C bin 1×1
      Integration:
      21h 20′
      Darks:
      20
      Flats:
      20
      Flat darks:
      19
      Avg. Moon age:
      8.51 days
      Avg. Moon phase:
      22.11%
      Bortle Dark-Sky Scale:
      7.00

      RA center: 07h28m53s.717

      DEC center: +13°1629.91

      Pixel scale: 0.276 arcsec/pixel

      Orientation: 29.447 degrees

      Field radius: 0.215 degrees

      WCS transformation: thin plate spline

      More info:Open 

      Resolution: 4998x2542

      File size: 7.0 MB

      Locations: StarzantiSkies Observatory, Orlando suburbs, FL, United States

      Data source: Backyard

      Description

      Abell 21 (Sh2-274), informally known as the Medusa Nebula, is not the most exciting object to image, but it does have some interesting features.  I tried to get a nice closeup but several nights of high thin clouds fought me on this effort.  So, unfortunately, it did not come out as detailed and clean as I had hoped due to poor transparency.  I minimized the stars to see if that would remove some distraction while looking at the nebulosity.  This planetary nebula, reclassified as such in the 1970s, is so large, its surface brightness is very low, with surface magnitudes reported between +15.99 and +25.  The central star of the planetary nebula is a PG 1159 star.

      Comments

      Revisions

        Closeup of Abell 21 (The Medusa Nebula) in SHO, 



    
        

            Bruce Donzanti
        Original
      • Final
        Closeup of Abell 21 (The Medusa Nebula) in SHO, 



    
        

            Bruce Donzanti
        C

      C

      Description: Slight adjustments

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      Closeup of Abell 21 (The Medusa Nebula) in SHO, 



    
        

            Bruce Donzanti