Celestial hemisphere:  Northern  ·  Constellation: Cepheus (Cep)  ·  Contains:  LDN 1177  ·  Sh2-136  ·  VdB141
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Ghost Nebula (LRGB), 



    
        

            Linda
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Ghost Nebula (LRGB)

Revision title: 2023 reprocessing

Getting plate-solving status, please wait...
Ghost Nebula (LRGB), 



    
        

            Linda
Powered byPixInsight

Ghost Nebula (LRGB)

Revision title: 2023 reprocessing

Acquisition details

Dates:
Oct. 6, 2021
Frames:
Astrodon Gen2 I-Series Tru-Balance Blue: 5×600(50′) -25°C bin 2×2
Astrodon Gen2 I-Series Tru-Balance Green: 12×600(2h) -25°C bin 2×2
Astrodon Gen2 I-Series Tru-Balance Lum: 32×900(8h) -25°C bin 1×1
Astrodon Gen2 I-Series Tru-Balance Red: 7×600(1h 10′) -25°C bin 2×2
Integration:
12h
Avg. Moon age:
0.03 days
Avg. Moon phase:
0.00%

RA center: 21h16m18s.606

DEC center: +68°1239.96

Pixel scale: 0.727 arcsec/pixel

Orientation: 179.008 degrees

Field radius: 0.349 degrees

WCS transformation: thin plate spline

More info:Open 

Resolution: 2540x2340

File size: 361.2 KB

Locations: Sierra Remote Observatories, Auberry, California, United States

Description

It seems October is when all the ghostly nebulae come out to play.

This is 12 hours of LRGB data on Vdb 141, the Ghost Nebula. Smoke cost a great deal of data, especially blue. Data was collected between October 1 and October 11, 2021. Smoke caused more than ½ the lum, and far more than ½ of the color filter data to be discarded. We would have kept going with acquisition but the waxing moon was going to interfere soon. Thankfully there was enough luminance to get a decent image out of this.


2023 Processing:

L:
dynamic crop
DBE
blurXterminator
starXterminator (extracting stars)
GHS

RGB
channel combination
dynamic crop
DBE
SPCC
blurXterminator
starXterminator (extracting stars)
GHS
LRGB in L
GHS (finished stretching)
lots of iterations of GAME/HT to lessen impact of halos
colormask_mod script selecting blue for blue in halos
range mask on the mask to soften it
SCNR on blue at 0.7 on blue to remove color cast in halo
LHE
MLT (very mild sharpening)
pixel math in stars (screen)

l stars:
ghs

rgb stars:
ghs
large combination in l stars
unsharp mask (very mild sharpening)

2021 Processing:

R, G and B:
dynamic crop
DBE

L:
dynamic crop
DBE
MLT noise reduction
histogram transformation

RGB:
channel combination
PCC
MLT noise reduction (chrominance only)
LRGB Combination to add in L
TGV denoise (very mild noise reduction)
EZ Star Reduction script
Curves for contras and color

I kept processing deliberately simple because it was relatively noise, especially in the chrominance so I didn't try to do much with contrast and avoided things like LHE and sharpening. There wasn't a lot of actual detail in this dust cloudy to really enhance anyway so sharpening seemed like it wouldn't do much at best.

Comments

Revisions

  • Ghost Nebula (LRGB), 



    
        

            Linda
    Original
  • Final
    Ghost Nebula (LRGB), 



    
        

            Linda
    B

B

Title: 2023 reprocessing

Description: see main text for details.

Uploaded: ...

Sky plot

Sky plot

Histogram

Ghost Nebula (LRGB), 



    
        

            Linda