Jellyfish nebulae Ced73/Ced74/IC443/IC444/LBN840/LBN841/LBN844/Sh2-248/Sh2-249/S


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Also includes Eta Geminorum/Propus, Mu Geminorum/Tejat, and LDN1564-LDN1568.

Total integration: 2218 minutes/37 hours (137/19 x 300/420s or 13.7h for Ha + 94/28 x 300/420s or 11.1h for O3 + 94/35 x 300/420s or 12.2h for S2).

Cameras: QHY163M (16mp mono) and QHY247C (24mp OSC) CMOS cooled to -20 and -15 degrees C.
Telescopes: Takahashi FC100DF Steinheil fluorite doublet and Stellarvue SV70T triplet apochromat refractors @ f/4.9 and @ f/4.8.
Reducers: Takahashi FC-35 (0.66x) and SFFR70-APO (0.8x).
Mount: Paramount MyT.
Filters: 1.25" Astrodon 5nm Ha, 3nm O3, 3nm S2 and 2" Baader UV-IR-Cut
Software: TheSkyX Pro, SharpCap, PixInsight, Topaz Studio 2.

Full resolution images are available at https://www.astrobin.com/enlic2/ and of the main image at http://ram.org/images/space/scope/1.4+7.4.5+6/ic443_nf_c_shorgb_2218m+823m+666m+729m_2218m_37h.jpg

The Jellyfish nebula (IC443) is the name given to a galactic supernova remnant situated in the constellation Gemini about 5000 light years from Earth. The remains of a supernova that exploded prior to the dawn of the Julian and Gregorian calendars is coincidentally bookended by two bright stars in the frame, Eta Geminorum aka Propus/Praepus/Tejat Prior on the right and Mu Geminorum aka Tejat/Calx on the left side.

The narrowfield framing shows the partial shell of supernova remnant (G189.0+03.0) with its distinctive Jellyfish shape in the bottom right quadrant interacting with the molecular clouds surrounding it above and to the left, seemingly as though it is striking them with bolts of lightning. The interactions of the remnant with its surroundings all around are what give rise to its eponymous shape. The four dark nebulae (LDN1565-1568) towards the left in the top half are situated within Sh2-249, which also includes IC444 and LDN1564.  The widefield framing (coming soon) showcases the full extended region of about 70 light years properly, also with Drizzle and LocalNormalization so that the banding goes away.

I once again did what I did earlier, i.e., imaged the target with two scopes to get two different framings and then combined all the data together, which was collected over two years. One of the difficulties I had with this particular target was that the moon would also rise up along with nebula when it would begin to appear in the sky for me (late fall) so there were several hours worth of exposure that had to be thrown away.  Given that it is a relatively bright object, I managed to collect enough signal to produce a decent series of images for each framing.  The narrowfield series consists of seven images: (A) Ha, (B) L (m-sho), and three colour combinations (C-E) of the SHO data created using the Ha data for luminance, the last two processed using TopazStudio. This is followed by two different colour versions (F,G) of the SHO data created using a synthetic luminance layer that is a mix of the same data.

I am genuinely curious as to what people think of the TopazStudio 2 based processing. In the "primary" image above, I use moderate/minimal TopazStudio 2 processing after first processing with PixInsight. The two images below are processing only with PixInsight and then full TopazStudio 2 processing (taking it to a 11). On my web page, the full processing one is what looks best, but on AstroBin, it looks like overkill so I picked the middle ground as the primary choice to post here. So I'm curious as to know what people think:

PI only: https://www.astrobin.com/enlic2/C/

Full TopazStudio: https://www.astrobin.com/enlic2/E/

As always, thanks for looking!

OTAs: C925 EdgeHD; Meade ETX80; Coronado SolarMax II; Stellarvue 70T; Obsession UC18; Takahashi FS128, FC100DF.
Mounts: AVX; LXD75; Paramount MyT.
Cameras: ZWO ASI120MC-S; Lodestar X2c; X2m; Canon T7i; QHY163M.