Hemisphere:  Northern  ·  Constellation: Perseus (Per)  ·  Contains:  PK149-09.1

Image of the day 12/23/2019

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    Hartl-Dengel-Weinberger 3 (HDW 3), 



    
        

            Peter Goodhew
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    Hartl-Dengel-Weinberger 3 (HDW 3)

    Image of the day 12/23/2019

    Getting plate-solving status, please wait...
      Hartl-Dengel-Weinberger 3 (HDW 3), 



    
        

            Peter Goodhew
      Powered byPixInsight

      Hartl-Dengel-Weinberger 3 (HDW 3)

      Imaging Telescopes Or Lenses
      APM Telescopes TMB - LZOS Apo refractor 152/1200
      Imaging Cameras
      QSI 6120wsg-8
      Mounts
      10Micron GM2000HPS II
      Filters
      Astrodon Blue · Lum · Green · Red · Astrodon SII 5nm · Astrodon OIII 3 nm · Astrodon 5nm H-Alpha filter
      Guiding Cameras
      Starlight Xpress Lodestar X2

      Acquisition details

      Frames:
      Astrodon 5nm H-Alpha filter: 76x1800" (38h) bin 2x2
      Astrodon Blue: 17x300" (1h 25') bin 1x1
      Astrodon OIII 3 nm: 51x1800" (25h 30') bin 2x2
      Green: 20x300" (1h 40') bin 1x1
      Lum: 39x300" (3h 15') bin 1x1
      Red: 20x300" (1h 40') bin 1x1
      Integration:
      71h 30'

      RA center: 03h27m16s.950

      DEC center: +45°2501.85

      Pixel scale: 0.534 arcsec/pixel

      Orientation: -3.716 degrees

      Field radius: 0.359 degrees

      More info:Open 

      Resolution: 4100x2577

      Locations: e-Eye, Fregenal de la Sierra, Extramadura, Spain

      Data source: Own remote observatory

      Remote source: e-EyE Extremadura

      Description

      Hartl-Dengel-Weinberger 3 (HDW 3, PK149-09.1, PNG149.4-09.2) is an extremely faint ancient planetary nebula in the constellation Perseus. It is so faint that it is very rarely imaged.

      The progenitor star is the small blue star at the 5 o-clock position just below the large yellow star in HDW 3. The progenitor is not, as one would expect, in the centre of the nebula. This is because it is moving rapidly in a north-westerly direction. It is moving through a dense area of interstellar medium (ISM). This ISM is slowing down HDW 3, creating a shock front and the unusual "braided" appearance. As the star isn't slowed by the ISM it has continued to move and is thus no longer at the centre of HDW 3 and is slowly overtaking HDW 3. This causes the shock front to be brighter as it's getting more ultraviolet radiation, whereas of opposite side of HDW 3 is getting less UV radiation and has become invisible. This movement of the star causes differential excitation of the shell. OIII emission, which requires higher energy of the ionizing radiation than HII emission, only happens close to the star.

      Comments

      Revisions

        Hartl-Dengel-Weinberger 3 (HDW 3), 



    
        

            Peter Goodhew
        Original
        Hartl-Dengel-Weinberger 3 (HDW 3), 



    
        

            Peter Goodhew
        B
      • Final
        Hartl-Dengel-Weinberger 3 (HDW 3), 



    
        

            Peter Goodhew
        C

      B

      Description: crop

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      C

      Description: small stars sharpened

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      Hartl-Dengel-Weinberger 3 (HDW 3), 



    
        

            Peter Goodhew