Hemisphere:  Southern  ·  Constellation: Puppis (Pup)  ·  Contains:  F Pup  ·  M Pup  ·  NGC 2451  ·  P Pup  ·  PK258-15.1  ·  PK259-09.2  ·  Puppis  ·  Q Pup  ·  The star σPup  ·  W Pup  ·  c Pup  ·  d01 Pup  ·  d02 Pup  ·  d03 Pup  ·  d04 Pup  ·  sig Pup  ·  y Pup

Image of the day 04/29/2021

Getting plate-solving status, please wait...
    BBW56, 



    
        

            Mathew Ludgate
    Powered byPixInsight

    BBW56

    Image of the day 04/29/2021

    Getting plate-solving status, please wait...
      BBW56, 



    
        

            Mathew Ludgate
      Powered byPixInsight

      BBW56

      Imaging telescopes or lenses: NIKON 200mm f/2

      Imaging cameras: ASI6200mm Pro

      Mounts: Rainbow Astro RST-135

      Software: Voyager  ·  Adobe Inc Photoshop CC  ·  PixInsight

      Filters: Chroma LRGB 50mm  ·  Chroma 8nm Ha SII OIII


      Dates:Feb. 19, 2021April 4, 2021

      Frames:
      Chroma 8nm Ha SII OIII: 90x300" (7h 30') (gain: 100.00) bin 1x1
      Chroma LRGB 50mm: 54x60" (54') (gain: 0.00) bin 1x1

      Integration: 8h 24'

      Avg. Moon age: 14.68 days

      Avg. Moon phase: 48.23%


      Astrometry.net job: 4430228

      RA center: 7h 33' 12"

      DEC center: -42° 27' 21"

      Pixel scale: 7.896 arcsec/pixel

      Orientation: 89.100 degrees

      Field radius: 6.190 degrees


      Resolution: 4734x3100

      Data source: Backyard

      Description

      BBW 56: a Windswept Molecular Mountain

      I started this project back in February, and it seemed to be a real magnet for high cirrus. So it’s taken a while, with a lot of subs thrown out, but it is nice to put it all together.

      This is another rarely imaged area. BBW56 is a large molecular cloud in the Gum Nebula and is surrounded by 9 cometary globules, including the famous CG4 ‘Hand of God’ originally imaged by David Malin. BBW56 itself is likely to have been shaped by a similar process to these adjacent CGs. While BBW56 looks like a mountain rising out of the depths, it is actually more an outcrop that is resisting the stellar winds that are blasting it from above.

      Revision B https://astrob.in/zjlatd/B/ is a starless version

      BBW56 and Cometary Globules
      Cometary globules are a special type of molecular cloud, which were first observed in 1976. They have a comet-like morphology, consisting of compact, dusty, opaque head, and a long, faintly luminous tail. It is thought that CG’s are caused when nearly spherical gas clouds are blasted and collapsed by a SN shockwave. The shock compresses the cloud to form the head, and the blast wave drives the material away from the SN to form the tail. An alternative mechanism is that CGs are formed when the UV radiation from massive O stars photoionizes the gas cloud and shock fronts compress the head of the cloud. The less dense parts of the cloud are separated from the head of the cloud by the radiation and ionization shocks, and the tail is formed out of this eroded cloud medium.

      Interestingly, most CG's are located in the Gum nebula. These Gum nebula CG’s are all located within a radius of 6 to 11 degrees from a central point, and have their tails pointing away from this central region. This suggests that they are all located at the edge of a large ionised bubble. The central sources of this ionisation are thought to be the supergiant O-type stars Gamma 2 Velorum and Zeta Pup, and the Vela SNR. The ionisation created by these three sources is incredibly intense, with Zeta Pup alone producing a fierce stellar wind blasting out at 2300 km/sec causing it to lose mass at 10 million times the rate of the Sun's solar wind. It is these winds that are blasting and shaping BBW56.

      Revision C https://astrob.in/zjlatd/C/ is an illustration of the location of the cometary globules in the Gum nebula (from Zealey et al. 1983) showing the consistent radius from the central point. I have superimposed my image of BBW56 for reference.

      Revision D https://astrob.in/zjlatd/D/ is annotated to show the cometary globules that surround BBW56.

      OIII Emission
      I decided to try to see if there was any OIII emission present, and was pleased to pick up a a fairly well defined, very faint cloud of OIII and Ha emission sitting above BBW56. I can’t find any sign of this cloud on prior images, and this may be the first image to capture this feature. This cloud has the same width and roughly the same outer contour as the BBW56 structure, and maybe the remnant of the gas cloud that has collapsed to form BBW56.

      Comments

      Revisions

      • Final
        BBW56, 



    
        

            Mathew Ludgate
        Original
        BBW56, 



    
        

            Mathew Ludgate
        B
        BBW56, 



    
        

            Mathew Ludgate
        C
        BBW56, 



    
        

            Mathew Ludgate
        D

      B

      Description: Starless Version

      Uploaded: ...

      C

      Description: Illustration of location of the cometary globules in the Gum nebula

      Uploaded: ...

      D

      Description: Annotated version showing the cometary globules that surround BBW56

      Uploaded: ...

      Sky plot

      Sky plot

      Histogram

      BBW56, 



    
        

            Mathew Ludgate