ngc 7640 and ugc 12588 in HaRGB - WIP

[wimvb]

Edit: scroll down for the LHaRGB version

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Astro season started with a cloud cover, but recently we've enjoyed a few gaps. There's still a lot of moisture in the air, but thanks to the Pegasus Power Box Advance and a dew band, I haven't had any condensation on my telescope.

Ngc 7640 is a barred spiral in the constellation Andromeda. The galaxy is slightly smaller than the Millky Way and about 24 Mly distant. As many other galaxies, the ones in this image are very seldom imaged with H-alpha filter. In my experience, if a galaxy shows blue "knots", that is an indication of star formation, and those young stars were at one time born from Hydrogen clouds. I decided therefore, to collect H-alpha and not just RGB.

This image consists of 78 4 minute exposures (about 5 hours) with a H-alpha filter, and 3 x 24 5 minute exposures with RGB filters, for a total of more than 11 hours of data. As usual, imaged with my SW 190MN and ASI294MM camera. I've also collected luminance data, but I didn't like the quality and haven't used it. Maybe I will collect new L when the weather allows.

Both galaxies have small H-alpha inclusions, and to my knowledge, this is the first amateur image to show these.

close up

 

****** New version with L ******

and close up

Edited September 27, 2023 by wimvb

[Mandy D]

Very nice! The 190 MN looks like a superb piece of kit.

[geeklee]

Great shot Wim, the Ha additions look fantastic and help identify the fainter arms even more clearly in NGC 7640.  Super colour in both galaxies.

[tomato]

Yes, the detail and colour are excellent, and the background is spot on. Any AI processing on this one?

[gorann]

Excellent Wim! The Ha really lifts it and details as well as sky look great.

[wimvb]

7 hours ago, tomato said:

Yes, the detail and colour are excellent, and the background is spot on. Any AI processing on this one?

Thanks. The xT suite of course. BxT for deconvolution. In my opinion, it would be possible to get similar results with "conventional" deconvolution, but BxT is just easier and allows sharpening of details that have a lower snr. StarxT is tricky on galaxy images because it tends to remove galaxy details and background galaxies as well. Here I used it with a mask to protect the main galaxies. Together with BxT it does a better job of keeping foreground stars under control than Morphological Transformation.

[wimvb]

8 hours ago, Mandy D said:

Very nice! The 190 MN looks like a superb piece of kit.

Thanks. It is, although I still have to do a tiny collimation tweak. The secondary wasn't properly centered under the focuser. Last spring I replaced the stock focuser with an Omegon low profile focuser and at the same time adjusted the secondary. On close inspection it looks like I should move the secondary a tiny bit more.

[tooth_dr]

Superb work, and the close up crop maintains all the detail and definition.

[wimvb]

The luminance data had several issues in the background, but I figured out a way to apply it to the galaxies alone. I just uploaded the not-so-wip version in my original post

LHaRGB, roughly 16 hours integration time