ngc 7640 and ugc 12588 LHaRGB - now with IFN and done

[wimvb]

No longer a work in progress. https://stargazerslounge.com/topic/414033-ngc-7640-and-ugc-12588-in-hargb-wip/ 

It turned out that shooting flats with the camera at -10 degrees and 96 % humidity isn't much of a hit. I had ice forming on the sensor which ruined the calibration. I shot new flats, now at +2 C to avoid freezing, and reprocessed the data from scratch.

The light frames weren't affected by the ice, either because I collected the data under better conditions, or simply because of the dithering and registration which reduced the effect.

This is what I got from the data. I think reprocessing the original data payed off.

Ngc 7640 is a barred spiral galaxy in the constellation of Andromeda. It is at a distance of 25 - 30 Mly and has a size of about 90,000 light years.

Ugc 12588 is a spiral galaxy at about the same distance. Its size is only about 18,000 light years

Both galaxies show signs of star formation, which is why I collected H-alpha data.

• 3 x 2 hours RGB
• 5 hours L
• 5 hours Ha

As always, I used my trusted MN190 and ZWO ASI294MM camera

Processed in PixInsight

[WolfieGlos]

That’s a great final image, love the star colours and faint fuzzies too.

[tomato]

Great colour and detail on the galaxies. I’m not a fan of images where the IFN takes precedence over the galaxies, but it is nicely balanced on your image.

[Rodd]

Wow--that MN190 is awesome.  Truly an amazing image.  I am not familiar with these and I need to look into them

[wimvb]

On 01/10/2023 at 16:30, WolfieGlos said:

That’s a great final image, love the star colours and faint fuzzies too.

Thanks, Chris. Yes there are quite a few fuzzies in the background. For some reason, no more than a handful are mentioned in Simbad/Vizier. This is uncharted territory in a way.

On 01/10/2023 at 17:37, tomato said:

Great colour and detail on the galaxies. I’m not a fan of images where the IFN takes precedence over the galaxies, but it is nicely balanced on your image.

Thanks. Detail on the galaxies could have been better in my opinioin. Warm autumn nights aren't the best for shooting galaxies. I agree with you aobut the ifn; it should be a whisper, not a shout.

51 minutes ago, Rodd said:

Wow--that MN190 is awesome.  Truly an amazing image.  I am not familiar with these and I need to look into them

Thank you, Rodd. After replacing the stock focuser and re-collimation, the scope is ready for another season.

[GalaxyGael]

Handsome image.

Which focuser did you use to replace the stock one? 

[wimvb]

2 hours ago, GalaxyGael said:

Handsome image.

Which focuser did you use to replace the stock one? 

Thanks, Colm. I originally planned to treat myself to a FeatherTouch focuser, but Astroshop kept pushing the delivery date forward. After one year, several mails, and reading about all the troubles Starlight Instruments was (still is?) going through, I did a bit more homework, and found that the Omegon Steeltrail Crayford focuser should match the MN190 base plate. I ordered that model and had money left to add a Pegasus AstromFocuscube, plus a Pegasus Astro powerbox advance. I'm happy with the replacement. It has much better stability than the original SkyWatcher low profile focuser with its wobbly built in extension tube.

[GalaxyGael]

Good to know. There are lots of feathertouch on TS optics for a long time now, even a few second hand ones in APM, but pricey. The powerbox advance is something I am interested in too. Nice upgrade for you.

I was contemplating the SW make newt. My mn56 corrected circle doesn't quite do aps c with the tiny secondary...and my atik 460ex usb 2 is so slow for autofocus and polar alignment😐, but otherwise a great sensor.

And a good idea to go with that SW base plate so your focuser position is unchanged for this type of scope.

Good luck with it this season

Edited October 3, 2023 by GalaxyGael

[wimvb]

2 hours ago, GalaxyGael said:

And a good idea to go with that SW base plate so your focuser position is unchanged for this type of scope.

Good luck with it this season

That was my main requirement. Thanks.

2 hours ago, GalaxyGael said:

My mn56 corrected circle doesn't quite do aps c with the tiny secondary

Do you need aps-c? I used the ASI174MM-Cool for a few years. Great little camera for dso, apart from the horrible amp glow. But if zwo ever release a cooled version of the ASI482 with 5.8 um pixels, I will be seriously tempted to get one.

I think that asian focusers have improved so much over the last few years that Starlight Instruments and the likes must be hard pressed to keep up. And with so much going on at that company, I wouldn't be surprised if they go out of business.

[GalaxyGael]

12 hours ago, wimvb said:

That was my main requirement. Thanks.

Do you need aps-c? I used the ASI174MM-Cool for a few years. Great little camera for dso, apart from the horrible amp glow. But if zwo ever release a cooled version of the ASI482 with 5.8 um pixels, I will be seriously tempted to get one.

I think that asian focusers have improved so much over the last few years that Starlight Instruments and the likes must be hard pressed to keep up. And with so much going on at that company, I wouldn't be surprised if they go out of business.

Agree, I use a TSFOCR25 on another refractor that is almost identical to FT in all practical aspects, very good. Focusers that comes with Askar are almost the new benchmark, really excellent stuff. I don't need APS-C per se but I have one and its USB 3 and generally prefer it to other cameras, so much easier to work with. I use the Atik 460ex 1-inch sensor on the MN56 which works pretty well.

I think there is alrady a move to release cooled version of planetary cameras. the 290 mm has been I think, so larger pixel cameras with slightly smaller sensors will have a following I think. Not from a FOV needs but for ease of field correction, well depth, and good sensible pixel scale in our skies for small targets, to me at least.