Stephan's Quintet / HCG92 and NGC7331 - 2 nights of trouble with the skies

[ONIKKINEN]

8 hours with an 8'' newtonian, TeleVue Paracorr, and a RisingCam IMX571 OSC camera:

Annotated version:

And a blown up crop of the Quintet itself:

Not going to compete with Hubble or JWST any time soon when the data is 3.5-4'' fwhm, but an image is an image. Will have to devote more time on this as the details seem like they could use some more quality data to tickle out the fine stuff in the cluster, weather willing of course. Find myself often saying the same, so this will go in the ever expanding target category of "needs more time" which at the moment would probably last me a few years at best to finish.

First night gave around 5 hours in early September with a 50% Moon and not great transparency. Second night was crystal clear with very good transparency, but the scope was sailing in high winds with an end total of 1.4'' RMS guiding error so a lot of the data had to be scrapped, and the data that made it just isn't very sharp because the scope was having a seizure in the wind every other minute. MacGyvered an impromptu wind shelter by stacking various items/bags used to carry the kit found in my car on the roof of my Ford Focus parked right next to the scope (the scope is much taller than the car, even at minimum tripod extension) which may have helped, if only by giving me something to do other than look at the seismograph that was the guide graph.

Comments, critique welcome!

-Oskari

Edited October 9, 2023 by ONIKKINEN

[Paul M]

Very nicely processed. Only looking at it on my phone but it looks great.

Nice stars too.

[ONIKKINEN]

1 hour ago, Paul M said:

Very nicely processed. Only looking at it on my phone but it looks great.

Nice stars too.

Thank you! I think i overprocessed it, like i usually do but glad to hear you like it.

I used CFA_split stacking, which creates perfectly RGB aligned stars and allows basically any amount of saturation to be applied on them without them showing chromatic issues around the edges. Despite the wind i still had good roundness in all the data, at a minimum of 0.75 roundess. Wind caused equal errors on both axis so no oblong stars as a result.

[Grant]

Wow!  That’s very impressive detail, love the star colours!

Lots and lots of galaxies in there 🙂

 

[ONIKKINEN]

1 hour ago, Grant said:

Wow!  That’s very impressive detail, love the star colours!

Lots and lots of galaxies in there 🙂

 

Thank you!

Indeed there are, and most seem to be without a PGC name, so probably quite distant.

[ONIKKINEN]

Fresh eyes and a new attempt at processing yielded this:

Less crunchy but with more IFN, maybe slightly more detailed? I prefer this one to the original.

Stacked a synthetic luminance image from all the CFA channels and used RGB data from the original image in the original post. Tried NoiseXT before BlurXT this time, and stretched with the hyperbolic stretch tool in Siril.

[Paul M]

Definitely softer, and from a purely aesthetic viewpoint, the stars are even nicer. Great diffraction spikes; proper stars!!