Squid nebula Ou4 (c-orgb)


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Squid nebula Ou4 (c-orgb)
« on: October 03, 2020, 03:31:14 PM »
Also includes: v419 Cephei.

Total integration: 3280 minutes/~55 hours (*632 x 300s for O3 + **60 x 120s for OSC).

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.

Full resolution images of all versions are available at https://www.astrobin.com/jdaa90/ and of the primary image at http://ram.org/images/space/scope/1.4+7.4.5+6/ou4_c_orgb_632x300+60x120_3280m_55h.jpg

The Squid nebula (ou4) occupies over one degree of the night sky, representing the largest angular extent ever found in a planetary nebula. Known colloquially as the giant squid nebula, it is physically nearly 50 light years across.  This bipolar nebula could be one of the nearest of its type known, though its possible planetary nebula nature needs confirmation.  Even though it is big and close, you're not likely to find it easily. It is an extremely faint nebula emitting primarily O3 signal and resides within the larger Flying Bat nebula (not shown here, yet) which tends to overshadow it, making it a challenging target to image.

The nebula is created by the outflow of material driven by a triple system of hot, massive stars catalogued as HR8119 (blue hypergiant) as well as the pulsating variable star v419 Cephei (red supergiant) seen near the center. While their shapes do their names justice, to me, the Squid seated within the Flying Bat more resembles a hand holding an infinity stone (viewed sideways).

This is the first image of my Flying Bat and Squid project/series, which became a huge undertaking for me, ending up with a total of more than 131 hours in the final integrated widefield image of both objects and a series of three main images with a few versions of each depending on the data set used for the integration.

In the first image, I am showcasing the Squid nebula by itself using only the O3 filter data, with and without RGB stars.  The mono Squid imaged with the Takahashi FC100DF consists of ~53 hours of total exposure in O3, making it my single longest total exposure of a target with a particular framing with a specific filter/scope/camera combination.  The RGB data collected using the QHY247C with the SV70T adds another two hours to the exposure.  The total integration for the version with RGB stars is ~55 hours.  I also captured another 5.5 hours of O3 data using my SV70T which is present in the final image in the series but I haven't created a separate Squid only version with that integration yet but I might if I get around to it.

There are six versions of the Squid only framing at https://www.astrobin.com/jdaa90/ --- the difference between the two monochrome versions of the Squid is the application of HDR Multiscale Transform which reduces the halo on the central star as well as the amount of data used: (A) is based on the full ~53 hours whereas (B) is based on the best 40 hours.  (C) and (D) are corresponding versions that combine O3 in the blue channel with RGB stars along with changes in the amount of saturation and brightness. Similarly with (E) and (F), but the Squid is in monochrome mixed with the RGB stars background. Finally (G) is a closer crop and extra sharpened version; I typically prefer to leave the entire star background if I can and this time I could because I used the RGB stars but this a version with some cropping and sharpening which looks great from afar.

After doing different versions of the Squid by itself, I worked on a narrowfield and widefield versions where it is situated between the wingspan of Flying Bat (coming soon). I started with data from the FC100DF/QHY163M combination which results in a total exposure of 78+ hours for SHO. The SV70T/QHY163M data used for the widefield framing representing another 51+ hours was also integrated in. The RGB data using the QHY247C with the SV70T adds another two hours.  The total exposure of the final image with the narrowfield or widefield framing is 131+ hours, my longest to date!

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.

Re: Squid nebula Ou4 (c-orgb)
« Reply #1 on: October 13, 2020, 03:01:37 AM »
Amazing pict!