Hemisphere:  Northern  ·  Constellation: Coma Berenices (Com)  ·  Contains:  IC 3946  ·  IC 3949  ·  IC 3955  ·  IC 3973  ·  IC 4040  ·  IC 4045  ·  IC 4051  ·  NGC 4860  ·  NGC 4864  ·  NGC 4865  ·  NGC 4869  ·  NGC 4871  ·  NGC 4873  ·  NGC 4874  ·  NGC 4881  ·  NGC 4883  ·  NGC 4886  ·  NGC 4889  ·  NGC 4895  ·  NGC 4898  ·  NGC 4907  ·  NGC 4908  ·  NGC 4911  ·  NGC 4919  ·  NGC 4921  ·  NGC 4926  ·  NGC 4927

Image of the day 04/22/2021

Getting plate-solving status, please wait...
    The Coma Cluster (Abell 1656) and Dragonfly 44, 



    
        

            Chen Wu
    The Coma Cluster (Abell 1656) and Dragonfly 44
    Powered byPixInsight

    The Coma Cluster (Abell 1656) and Dragonfly 44

    Image of the day 04/22/2021

    Getting plate-solving status, please wait...
      The Coma Cluster (Abell 1656) and Dragonfly 44, 



    
        

            Chen Wu
      The Coma Cluster (Abell 1656) and Dragonfly 44
      Powered byPixInsight

      The Coma Cluster (Abell 1656) and Dragonfly 44

      Technical card

      Imaging telescopes or lenses: Takahashi FSQ-106EDX III  ·  Takahashi TOA-130NS

      Mounts: Astro-Physics AP1100GTO-CP3

      Guiding telescopes or lenses: ZWO OAG

      Guiding cameras: ZWO ASI174Mini

      Software: Adobe Phosotshop CC  ·  PixInsight  ·  Starkeeper.it Voyager Custom Array  ·  AstroPixel Processor

      Filters: Chroma R 50mm  ·  Chroma B 50mm  ·  Chroma G 50mm  ·  Chroma Lum 50mm  ·  Chroma 5nm Ha 50mm

      Accessory: Takahashi 67-FL Flattener  ·  Moonlite Nitecrawler WR35  ·  虫子 WormCover & WormFlatPanel


      Dates:March 6, 2021March 14, 2021March 17, 2021March 18, 2021March 31, 2021

      Frames:
      Chroma B 50mm: 46x300" (3h 50') (gain: 0.00) -10C bin 1x1
      Chroma G 50mm: 46x300" (3h 50') (gain: 0.00) -10C bin 1x1
      Chroma Lum 50mm: 161x300" (13h 25') (gain: 0.00) -10C bin 1x1
      Chroma R 50mm: 46x300" (3h 50') (gain: 0.00) -10C bin 1x1

      Integration: 24h 55'

      Darks: ~20

      Flats: ~20

      Bias: ~20

      Avg. Moon age: 9.96 days

      Avg. Moon phase: 34.56%

      Bortle Dark-Sky Scale: 2.00

      Temperature: 10.00


      Basic astrometry details

      Astrometry.net job: 4390538

      RA center: 13h 0' 26"

      DEC center: +27° 57' 3"

      Pixel scale: 1.545 arcsec/pixel

      Orientation: 77.449 degrees

      Field radius: 0.505 degrees


      Resolution: 1413x1884

      Locations: Dark Sky New Mexico, Animas, New Mexico, United States

      Data source: Own remote observatory

      Remote source: Dark Sky New Mexico

      Description

      Spoiler: Dragonfly 44 is not presented in the original revision but revision E.

      I came to learn about Dragonfly 44 back in maybe 2017 through Sky & Telescope. A research team assembled 10+ Canon 400mm f2.8 lens array from a remote dark site. They made the discovery and took the picture of the unknown diffuse galaxy at that time.

      I recall I read that even the Hubble telescope scanned the region five times before locating the object. I couldn't find the citation now.

      Wiki says its magnitude is about 21. It's way far beyond my reach when I was shooting from backyard or even from our club's dark site (class 4). I have been salivating though it was obviously a quite luxurious thought to take a picture of it.

      Now it's a totally different story. Being at one of the best remote sites, our 300s gain 0 lum subs (asi6200mm) can easily capture mag 22+ targets after integration. Even squeezing MaskGen in PixInsight with the latest DR3 database to its very limit couldn't cover the tiniest stars in our masters. Interestingly, my friend Joe has made a successful attempt last year after two whole nights of imaging.



      I figured it's time to see the limit of our equipment and seeing condition. Though this target is about Abell 1656 (Coma Cluster), the full FOV is intentionally oriented to accommodate the dark target. There is no crop in revisions E/F.

      I'd say under our class 2 sky, the performance of the optics is expected. Besides this faint Dragonfly 44, a lot other objects are on par or even darker. Enjoy finding and looking!

      Ps, Hubble/ESA released the data of NGC 4291 in 2016 and a magnificent processing won APOD in 2019.



      It is the grand design spiral galaxy in the lower central part of my picture.

      #TeamNoctuaDSNM

      Comments

      Revisions

      • Final
        The Coma Cluster (Abell 1656) and Dragonfly 44, 



    
        

            Chen Wu
        Original
        The Coma Cluster (Abell 1656) and Dragonfly 44, 



    
        

            Chen Wu
        E
        The Coma Cluster (Abell 1656) and Dragonfly 44, 



    
        

            Chen Wu
        F

      E

      Description: Full FOV (asi6200mm) on TOA130

      Uploaded: ...

      F

      Description: Full FOV with annotation

      Uploaded: ...

      Sky plot

      Sky plot

      Histogram

      The Coma Cluster (Abell 1656) and Dragonfly 44, 



    
        

            Chen Wu

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