Ceph Impression -- Sh2-171 (NGC 7822) -- The Skull Nebula (G400)

Ceph Impression -- Sh2-171 (NGC 7822) -- The Skull Nebula

This is my first step in approaching narrowband imaging.

Yesterday the SCT-Duo-Narrowband (Ha & OIII) clipfilters arrived for the Canon cameras on my Dual Cat Rig and we had a second clear night in a row. What a perfect match! :-)

The rig was running from 11pm to 5am in the morning without any hickups. So integration time of approx. 12hrs was gathered during the night which was processed in the so far used RGB workflow.

Next step will be the cfa splitted into the R G G B components being treated thereafter seperatedly (new terrain to me and thanks a lot to Fritz for the description of the workflow) before recombinging and blending them thereafter with another 8,5 hrs of RGB data aquired the night before on this object. New high watermark in integration time :-)

With respect to the new filters I have to say that I had expected more halos around the stars especially @ ISO 1600 with a moon still illuminated at approx. 66% and 600s per frame. There are some but to a very moderate degree which I hope can be handeld during further processing. So in that regard I was pleasently surprised!

C&C very welcome.

Clears Skies

Andreas

B

Description: Applied some gentle denoising via ACDNR and a 90° rotation of the frame.

Uploaded: ...

C

Description: cfa split --> channel recombination with R=CFA0, G=CFA0*0,25+CFA2*0,75, B=CFA3 --> tweaked the curves a Little --> removed the (the smaller) stars

Uploaded: ...

D

Description: smaller stars added back

Uploaded: ...

E

Description: D as portrait version

Uploaded: ...

F

Description: Sharpened the core of Sh2-171 and denoised the whole frame.

Uploaded: ...

G

Description: Reproduction of the cfa split workflow.

Uploaded: ...

H

Description: Final Version -- Added another 8.5 hrs of RGB-data or RGB-stars respectively --> arriving at a total of 21.2 hrs of total integration --> New high watermark :-)

Uploaded: ...

I

Description: Less Red.

Uploaded: ...

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Status	Advanced success
Started	...
Astrometry.net job	2971351
PixInsight job	AWE2T467P9RNVAWIS9C9NZGLB2LMD26H
PixInsight queue size	n/a
PixInsight stage	n/a

RA (center)	00h03m07s.91
RA (top/left)	00h16m07s.15
RA (top/right)	23h38m22s.51
RA (bottom/right)	23h52m52s.95
RA (bottom/left)	00h23m55s.54

Dec (center)	+66°38′26″.8
Dec (top/left)	+69°30′57″.3
Dec (top/right)	+68°41′28″.7
Dec (bottom/right)	+63°42′49″.5
Dec (bottom/left)	+64°23′10″.6

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