SH2-136 - The Ghost Nebula in Cepheus (Astro with Eric)

SH2-136 - The Ghost Nebula in Cepheus

Continuing my summer imaging season with a trip back to see the King. SH2-136 is a reflection nebula near NGC 7023, the Iris Nebula. The Ghost is about 1500 light years away and spans across over 2 light years. There are a lot of awesome dark clouds and young bright stars that cause the nebula's eerie illumination while giving it a brownish tint. The shape looks like people with their hands up giving it that spooky vibe.

This project was quite shorter than my earlier July project, WR-134, only a couple of nights and imaged only in LRGB. Processing is always a lot of back and forth for me. This image was done almost exclusively in Pixinsight, integration, and post. I tried different methods to control the stars as well as deciding the best use of the luminance layer. This time I used StarXterminator to completely remove the stars in both the L and RGB images, using BlurXterminator on the L channel and it surprisingly gave a nice bit of extra definition on the nebulosity. For the RGB, I made a clone for stars and starless and tried Bill Blanchard's PixelMath star reduction methods but in the end, I used Morphological Transformation to get the results I felt were best for the stars for this project. I used Histogram Transformation for the stretches for both L and RGB (I'm still planning to use the GHS script at some point on a project). For the RGB I added a dash of HDRMST, a sprinkle of Curves, a pinch of LKE for contrast, SCNR to toss out the green, PM to return the stars, then an LRGB combination to blend the channels back. But with all my back and forth to find what I think might look better on the RGB side, the post took about 3 hours, then put the TIF in Lightroom to make some minor final tweaks and to add the watermark.

CMOS Imagers

	Distinct awarded users	Total awarded images
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	Image of the day	Top pick	Top pick nominations	Total submitted
Deep sky
Solar system
Extremely wide field
Star trails
Northern lights
Noctilucent clouds
Landscape

	Image of the day	Top pick	Top pick nominations	Total submitted
Backyard
Traveller
Own remote observatory
Amateur hosting facility
Public amaeteur data
Professional, scientific grade data
Mix of multiple sources
Other
Unknown

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Status	Advanced success
Started	...
Astrometry.net job	8091394
PixInsight job	B7K6MIP5H67IW2MPZHBIR3MGQ5H312XI
PixInsight queue size	n/a
PixInsight stage	TASK_LOG

RA (center)	21h16m26s.68
RA (top/left)	21h11m47s.88
RA (top/right)	21h21m17s.35
RA (bottom/right)	21h21m16s.71
RA (bottom/left)	21h11m24s.36

Dec (center)	+68°14′54″.8
Dec (top/left)	+67°46′55″.4
Dec (top/right)	+67°48′03″.7
Dec (bottom/right)	+68°42′23″.2
Dec (bottom/left)	+68°41′15″.4

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