Hemisphere:  Northern  ·  Constellation: Cepheus (Cep)  ·  Contains:  NGC 7023  ·  VdB139
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Iris Nebula NGC 7023 (Ha OSC Lum), 



    
        

            Chris White
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Iris Nebula NGC 7023 (Ha OSC Lum)

Getting plate-solving status, please wait...
Iris Nebula NGC 7023 (Ha OSC Lum), 



    
        

            Chris White
Powered byPixInsight

Iris Nebula NGC 7023 (Ha OSC Lum)

Acquisition details

Dates:
Aug. 28, 2017
Frames:
ZWO 1600MC-C OSC: 106×180(5h 18′) (gain: 76.00) -20°C
ZWO Ha - 7nm: 63×240(4h 12′) (gain: 200.00)
ZWO luminance: 463×120(15h 26′) (gain: 40.00)
Integration:
24h 56′
Darks:
35
Flats:
50
Flat darks:
50
Avg. Moon age:
6.63 days
Avg. Moon phase:
42.00%

RA center: 21h02m00s.266

DEC center: +68°0545.20

Pixel scale: 0.964 arcsec/pixel

Orientation: 49.919 degrees

Field radius: 0.631 degrees

More info:Open 

Resolution: 3794x2795

File size: 7.0 MB

Description

Disclaimer: I worked with two new (to me) PI tools that I am not familiar with: arcsinh and tvgdenoise

This image is from an OSC/MonoLum/MonoHa combination. It started out as just an OSC. I purchased a color ZWO 1600cool back during NEAF so I could pair it up with a small refractor on a portable imaging setup. I’m doing an NB project now with the refractor so I tossed the OSC on the Newt to see what it could do on the Iris Nebula.

I collected a little over 5 hours of data and decided that with this image and another I had made, that OSC data collection just isn’t for me. I want the freedom of shooting NB all the time, and I do believe that combining Lum with RGB data is really a better use of my dark time. (YMMV).

So, I ordered up another 1600mm mono and with my scope still pointed towards the IRIS started gathering Luminance data. While I gathered this data over the course of the last few weeks, I also started working with arcsinh tool in PI, which does a remarkable job at preserving color throughout the stretch. By using this tool, I was able to retain colors within the IRIS and noticed that there were some red hues and a more purple tone to the reflection nebula than I had seen in most “blue” presentations of this target. I kept calibrating, and massaging the data to see if I was just off on my processing, but the more I worked it the more I became convinced that this target is not strictly a reflection nebula.

The more Lum I added, the more the subtle red started to show up, so I became convinced that there were some HA emissions in there. Imaging this target became a true exploration for me, as I sought to either prove that the Ha was in my imagination, or to validate my gut feeling that there was a signal being drowned out by the bright reflection component. After I collected about 10 hours of Lum I switched over to an Ha filter and began collecting data. As the subs rolled in I could instantly see a weak Ha signal surrounding the Iris itself. What surprised me, is that after integrating a little over four hours of Ha, it turned out that not only the Iris itself is shrouded in Ha, but that the entire field of dust also has a distinct Ha component. I think that this is why the dust in this area tends to have a slightly rusty brown color to it in super wide field images that bring out IFN in the area.

Lastly, I decided to get another night of Lum to clean everything up and here is the result from about 25 hours total of this mix of data sources. This was imaged with an 8” newt at 800mm focal length and f4. A combination of OSC, Ha and Luminance.

C&C most welcome!

Comments

Revisions

  • Final
    Iris Nebula NGC 7023 (Ha OSC Lum), 



    
        

            Chris White
    Original
  • Iris Nebula NGC 7023 (Ha OSC Lum), 



    
        

            Chris White
    B

B

Description: Boosted the dust a little...

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Iris Nebula NGC 7023 (Ha OSC Lum), 



    
        

            Chris White

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