Hemisphere:  Northern  ·  Constellation: Cepheus (Cep)  ·  Contains:  Iris Nebula  ·  NGC 7023  ·  NGC7023  ·  PGC2817439  ·  Sh2-136  ·  T Cep  ·  VdB139  ·  VdB141
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NGC 7023 SH2-136  The Iris and ghost 2-panel mosaic, 



    
        

            Alan Brunelle
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NGC 7023 SH2-136 The Iris and ghost 2-panel mosaic

Getting plate-solving status, please wait...
NGC 7023 SH2-136  The Iris and ghost 2-panel mosaic, 



    
        

            Alan Brunelle
Powered byPixInsight

NGC 7023 SH2-136 The Iris and ghost 2-panel mosaic

Imaging telescopes or lenses: Celestron RASA 11

Imaging cameras: ZWO ASI071MC PRO

Mounts: Celestron CGX-L

Guiding telescopes or lenses: Agena Astro Finder Scope

Guiding cameras: ZWO ASI 120 MM Mini

Software: IrfanView  ·  Pleiades Astrophoto PixInisight 1.8 Ripley (x64)  ·  Cartes du ciel  ·  Sequence Generator Pro  ·  PHD2  ·  Wolfgang Zima Mobile Observatory 3 Pro

Filters: Optolong L-Pro 2"

Accessory: Baader Planetarium RASA 11 UFC system with 2" filter slider


Dates:June 18, 2020

Frames: 32x240" (2h 8')

Integration: 2h 8'

Avg. Moon age: 26.86 days

Avg. Moon phase: 7.84%


Astrometry.net job: 3965736

RA center: 21h 8' 42"

DEC center: +68° 13' 48"

Pixel scale: 1.603 arcsec/pixel

Orientation: 165.523 degrees

Field radius: 1.606 degrees


Resolution: 5911x4138

Data source: Backyard

Description

While the data for this was collected mid June this year, the theme for me seems to continue with regard to my attraction to clouds of dust. (I have noticed that dust is also attracted to me!) Both NGC 7023 and SH2-136 are highlights to a vast area of dust. While they are visually close, from our perspective I really cannot say if they are really related to each other spatially. The Iris cloud to me seems much more explosive, almost radiating out from the apparent core while the ghosts appear much more tranquil, somehow being impacted from above from some unknown pressure that is compressing the dust. Perhaps they are distant to each other with the closer Iris superimposed by the less dramatic ghost clouds beyond...

But what is striking to me, and to continue a theme (at least in my mind, along with my NGC 1333 image is the fact that there is so much dust in what is clearly star forming regions yet we see so little hydrogen, by way of Ha emissions. It may well be there, hidden by some mechanism that quenches its Ha signal. Maybe the dust itself poisons that reaction. But there appears to be a perfectly hot blue star at the heart of the Iris that should emit plenty of UV light to fire up that hydrogen and show us. Maybe someone with an Ha filter can find it. To be sure, I can detect a bit of pink light on the surface of some of the illuminated clouds near the hot blue star. But it is weak and could be simple black body light from simple heating. A NASA site describes the red hues in the Iris as due to some unknown chemical compound fluorescing. In fact, the Iris hosts many Young Stellar Objects and IR sources along with Cepheid variables, etc. So there ought to be some hydrogen!

Upon starting this hobby and seeing these types of objects by my own hand, this has raised a whole host of questions as to what is going on. Hydrogen, oxygen and the other gases typically found in the universe are transparent. When we see dark clouds in the galaxy, these are not gas clouds. Yes, there no doubt is true gas associated with these, but they are neutral gas and not visible in our gear. The beautiful colors we see from these gases is because they can become excited by UV light emitted by large hot stars. We know that the universe as a whole is becoming more metal-rich as time goes by. If the Big Bang models are correct, there was no dust at all when the first stars lit up. And through various mechanisms of stellar destruction, more and more dust is accumulating in our universe as time goes by. (Think of this implication as it relates to life as we know it! That means the odds for life arising should increase with time, not just for statistical reasons, but for mechanistic reasons.) These molecular dust clouds stand in stark contrast to the vast star forming "bubble" nebula such as the Rosette, Misty Clover, Heart, Soul, etc.

One question I have for a star expert, is if there are clouds of dust, blown clean of gas by solar winds and extreme illumination, what becomes of those? Would we not expect these clouds of particles to also condense into large bodies through gravitational forces? We hear so much of star formation, either isolated or in clusters, but rarely or never of non-stellar large (stellar) mass bodies consisting less of gas and more of metals. What is the theory on those? If they are thought not to exist, then why? A body condensing of mostly dust but of stellar mass (by my meaning bodies otherwise large enough to have fusion if it was mostly hydrogen) should be very hot from heat of condensation and even significant fission radioactivity. What are these called? Brown dwarfs are just stars of insufficient mass to fuse. These would be potentially bigger.

The Iris was one of the first objects that I did last year (2019) with my new setup. I had wanted to return to it at a better time, so I did this mid June and when I learned that the ghost was close by, I decided that I had to have the two in the same frame, so made this a 2 panel mosaic. 30 subs on the Iris side and 32 on the Ghost side. I had taken a lot more, but most were not satisfactory. I guess that I can say that I got it, but I am not too satisfied with the result. So either I eventually I go back and work on this some more, or better yet, collect more and better subs. Either way, I do not intend to rush to do either.

Comments

Revisions

  • NGC 7023 SH2-136  The Iris and ghost 2-panel mosaic, 



    
        

            Alan Brunelle
    Original
  • NGC 7023 SH2-136  The Iris and ghost 2-panel mosaic, 



    
        

            Alan Brunelle
    B
  • Final
    NGC 7023 SH2-136  The Iris and ghost 2-panel mosaic, 



    
        

            Alan Brunelle
    C

B

Description: While reading comments on my cell phone this morning I notice that this image looked particularly dark on my phone, which has a very nice OLED display. I am concerned that my stretches while viewed on my desktop may not be translating very well to other monitors. So I decided to tweak the stretch on this in case that is a problem for viewers who may be interested. I will still try to keep the original version on as the top image since I am not at all confident that my phone may actually be the culprit. But there should be clouds evident throughout the image with just a few gaps here and there.

Uploaded: ...

C

Description: Resubmitted the original so it is the on this image's homepage. B is only in case my monitor is not well calibrated and you want to see a more stretched image.

Uploaded: ...

Sky plot

Sky plot

Histogram

NGC 7023 SH2-136  The Iris and ghost 2-panel mosaic, 



    
        

            Alan Brunelle