NGC 1291-A Really Faint Fuzzy

[Russ.Carpenter]

This image and text were just uploaded to Astrobin. https://www.astrobin.com/qctfjj/

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NGC 1291 and its Dwarf Companion

NGC 1291 is a well-known ring galaxy that has an unusual inner bar and outer ring. It has been imaged and described many times, but its elusive dwarf companion has been ignored. My main mission was to capture this tiny object. And there it is! To the lower left of the main galaxy.

NGC 1291 meets the requirements of the Catalog of Southern Peculiar Galaxies and Associations, by Halton Arp and Barry Madore. It satisfies Category 8-galaxies with apparent companions, and Category 20-Dwarf Galaxies (Low Surface Brightness).

Tech Notes for ASA 500/3.6:
ASA Newtonian, 500 mm aperture, 1900mm focal length, F3.6
FLI Proline 16803, 9 μm pixel, 4096 X 4096
ASA DDM85 equatorial mount
Processing with PixInsight, StarTools, and Affinity Photo

[Mike in Rancho]

Amazing, as usual!

So, the Snow Collar Galaxy also has two different NGC designations, which threw me off for a few minutes. I wonder why that is.

I am unable to find a name for the elusive companion you picked up, even if I turn on every DSO catalog that Stellarium offers. And I have the extended DSO database installed. It is also a barely noticeable smudge if the Digital Sky Survey map is turned on.

However, there are a number of entries from the PGC that you (of course) captured in the FOV, including a nice and not-that-fuzzy PGC 88084 (which sounds like an old CPU) next to HIP 15252. This might be a very fun image to annotate with say, ASTAP's Hyperleda database. It would also be interesting to find out what faint mag stars you are picking up. That too may go beyond what I have in Stellarium - which is all the star catalogs they offer.

Another interesting tidbit, this Peculiar Southern is actually not out of reach. Well, the Snow Collar anyway. Although it looks like this may have been a better end-of-year target than for January, from 34N it is currently transiting at about 7:30pm close to 15° alt. That's doable, if it can be pulled out of the horizon LP and extinction. I would also be equipment challenged too of course.

[Russ.Carpenter]

Mike, what excellent detective work! Sometimes, I wonder if I over-use Super Structure. It's a great tool, but maybe I'm accidentally nuking some really interesting things in the background.

In fact, when my fellow members of Sonora Desert Astro Imagers look at StarTools pics, they often remark on the glorious backgrounds. Star fields could be a whole new hobby.

Thanks again for checking in.

Russ

[Mike in Rancho]

Thanks, Russ. Well everything is a compromise, and a nice background is for sure something to strive for. I am always looking to make sure it's not a noisy mess, even if the main target can handle a certain level of stretch.

I presume you mean the default-on-entry SS algorithm for DimSmall? It can nuke some faint stuff (though a lot of it deserves it), even in 1.8 which has altered the default gamma setting of DimSmall to 0.75. That of course can be adjusted further. Usually though, if I feel that a run of SS pushed back too many stars, or turned some details to mush, I'll pull back the strength setting to 75 or even 50%. And on this particular image, with a quite narrow field of view, I think the Airy disk percentage could be increased? Currently trying to learn more about that in another thread actually.

I had a rough time trying to get ASTAP to solve your image. Nearly gave up, but eventually I got it to work. Lots of fun little toys in ASTAP. Once solved, it reported back a FOV height of 0.64°, a focal length of 1940mm, based on 9µm pixels, and limiting magnitude of 20.6. Of course the image is already processed so I'm not sure of the validity there.

The hyperleda annotation showed a good number of little galaxies even in this tiny field, though sadly it did not have an identification for the faint fuzzy you pointed out at the beginning - even though it's more obvious than many of the PGC numbered fuzzies. Odd. That said your image has a large number of other galaxy candidates that also aren't ID'd.

I tried to keep the resolution here (presuming it lets me load it), but did have to up the jpg compression to get to 500kb.

NGC1291 from a-bin Russ Carpenter annotated.jpg (497.63 KiB) Viewed 2543 times