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Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 6:00 am
by ram
Also includes: v419 Cephei.
ou4_O3.v1.28_480.jpg
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 ... 0m_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 image with that integration yet but I might if I get around to it.

There are six versions of the Squid only image 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.

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 in a separate thread). 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!

--Ram

Re: Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 7:06 am
by Jockinireland
That is a fantastic image Ram. The amount of detail is just superb. Well done on your perseverance on the project and on the final image(s). I look forward to seeing the version with the bat but having the squid isolated like this is unusual but I think good as it takes away the distraction of the surrounding red Ha.

Re: Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 7:09 am
by Peter802
Ram.
Thank you for sharing this amazing image.
Looks that you have got yourself a full time project.
I look forward to seeing more images in this series.
Thank you for the share.

Re: Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 7:19 am
by MariusD69
Wonderful! Great work, Ram!!

Re: Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 7:30 am
by yobbo89
superbly done ram! :)

Re: Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 9:18 am
by Graeme1858
Outstanding dedication!

Lovely image.

Regards

Graeme

Re: Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 11:22 am
by JayTee
Ram,

To say this image is fantastic or stupendous is an understatement. It is masterful!

Superbly done,
JT

Re: Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 11:24 am
by carastro
Quite incredible. What dedication, and so many hours work, where do you find enough clear skies?

Have you got a final version together with the Bat?

Carole

Re: Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 11:24 am
by BABOafrica
[quote=ram post_id=116287 time=1601704828 user_id=231]
Also includes: v419 Cephei.

Total integration: 3280 minutes/~55 hours ...

... making it a challenging target to image.

Ghostly looking creature. Astounding detail, all the same.

BABO

Re: Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 11:46 am
by ram
Thank you all - I appreciate your kind words.

Carole, thanks. Luck I suppose - I actually feel I could use the time better but I was really busy with work until the end of last month it was just easy to keep going on this (and my other target IC443 I'm still trying to collect more data). For me, starting a new target is always more work than collecting data on an existing one so this one was an easy one to keep going on and I try to do one new target per moon cycle if it's a long project like this. We had a great August so most of it was done then. Besides being convenient, I also find the longer projects more satisfying. Before I got into AP, I did a lot of EAA and/or used remote telescopes there're hundreds of lo-fi images I've taken so I've done the "multiple images per night" thing before. At least with this much data I can put a lot of PI's signal processing statistics to the test. Finally as I reprocess some of my very first images due to gain in skill, I realised in many cases the problem is that I didn't collect enough data so I'm making sure that I collect enough that when I get better at this, the extra data will come in handy. Last year I did a 76 hour target and it came out okay but given what I know now, I believe I can do a LOT better on it and I have all that data to do it with.

That's a bit long winded for a rhetorical question, sorry!

As far as the final version of the Bat, no, I've not processed all the data yet (but I have collected enough). It's tricky since I have to integrate different exposure lengths and not sure what the best way is. I do have some test framings and such to see how I can integrate heterogenous data but it was done with a limited amount (about 1/5th of the total exposure so I could experiment more rapidly). Here's what the final wide field will look like for instance but this is like an early draft: http://ram.org/images/space/downloads/Image40.jpg

Thanks again! I hope everyone is staying safe and having clear skies!

--Ram

Re: Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 6:11 pm
by Graeme1858
Congratulations on the APOD Ram

A very worthy winner.

Regards

Graeme

Re: Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 6:21 pm
by Ruud
I tried to see the full version, but loading stopped after 12 minutes and 3/4 of the image. I'll try again later because the part I got to see is really good!

Congrats on the APOD!

Re: Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 6:54 pm
by KathyNS
WOW!! That is an ultra-faint target. But 55 hours of data pays off. Well done! That definitely deserves the APOD award.

Re: Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 7:00 pm
by Makuser
Hi Ram. Wow, 55 hours of data collection, but it was time well spent. A superb Squid Nebula image with an excellently detailed shape. Thanks for sharing this work with us Ram, and congratulations on winning the well deserved TSS APOD Award today.

Re: Squid nebula Ou4 (c-orgb)

Posted: Sat Oct 03, 2020 11:59 pm
by Hankmeister3
It's the most sensibly rendered Squid Nebula image I've seen of this DSO. It doesn't appear "over-processed" given the over-all smooth but delicate features within the nebula itself. Very nice stars, too. Super image, Ram. Thanks for sharing. Unfortunately there isn't a lot of color to this nebula which is probably why it looks so "ghostly" to me. Given the sheer length of this nebula, its mirror-image symmetry is quite remarkable in my view.

This image would make a great black velvet ionized Calamari art piece! Heh!

BTW, what kind of ionized gases would create this sort of blue-white coloration?

Re: Squid nebula Ou4 (c-orgb)

Posted: Sun Oct 04, 2020 1:50 am
by ram
Hank, thanks!

It's only O3 filter data aside from two hours. So it's all likely O3 or at least anything that emits that goes through that bandpass (O3 Astrodon 3nm). I believe there are other more complex molecule ionisations that may overlap with the O3 bandpass but Occam's razor is that it is O3 signal. There's nothing in Ha and S2.

So the colouring is artificial like with all narrowband images. I'm just assigning the O3 signal to the blue channel (mostly) which is what I'd end up doing in the final SHO image.

If you look at the Astrobin link, I provide the monochrome images which I think truly reflect what is being obtained from the filter. It'd be interesting to image this with an RGB set up and see what colour we get for the Squid. The two hours I did in RGB didn't get me anything in blue though I could see a fair amount of the bat in red. But then again, this is a very faint target.

The symmetric makes it known as a "bipolar nebula." Something I didn't know myself until this target. There was a paper I was reading about how these shapes happen

--Ram

Re: Squid nebula Ou4 (c-orgb)

Posted: Sun Oct 04, 2020 6:14 am
by John Baars
A great image. And a huge effort collecting and ordening data.
Congratulations with the APOD!
The nebula itself looks a bit spooky to me. I strongly advise other viewers to click the full version in the link.

Re: Squid nebula Ou4 (c-orgb)

Posted: Sun Oct 04, 2020 8:56 am
by OzEclipse
Oh wow, that's beautiful. Congratulations on the APOD
Joe

Re: Squid nebula Ou4 (c-orgb)

Posted: Sun Oct 04, 2020 9:22 am
by carastro
ram wrote: Sat Oct 03, 2020 11:46 am Here's what the final wide field will look like for instance but this is like an early draft: http://ram.org/images/space/downloads/Image40.jpg
It's going to look Amazing.

Carole

Re: Squid nebula Ou4 (c-orgb)

Posted: Sun Oct 04, 2020 3:11 pm
by helicon
Just a beautiful image Ram. Congrats on winning the APOD.