Adreneline

Thanks @wimvb and @PhotoGav . I had found formulae but was not confident in their use. All noted for future reference. 🙏

My knowledge does not go as far as calculating distance from redshift. How do you do the calculation ( accepting the uncertainty)? LEDA 1650398 -- Galaxy Other object types: G (2016RAA,LEDA), Opt (LAMOST,SDSS) ICRS coord. (ep=J2000) : 142.67269037 +21.45612886 (Optical) [ ] C 2020ApJS..249....3A FK4 coord. (ep=B1950 eq=1950) : 09 27 51.56168 +21 40 35.1496 [ ] Gal coord. (ep=J2000) : 208.62660025 +44.19877366 [ ] Radial velocity / Redshift / cz : V(km/s) 20955 [~] / z(spectroscopic) 0.072523 [~] / cz 21741.85 [~]; (Opt) E 2018MNRAS.474.1873W

Great image and very interesting plate solve - so much to look at. I was drawn to PGC1650398 because it looks like two interacting galaxies, so I took a closer look in Simbad which appears to confirm just that: I couldn't seem to find how far away this is though - needs an expert! You could spend hours investigating this lot! Thanks for sharing.

The only time I have seen something similar is when I have been creating large mosaics in APP, and even then it was only on the very large Cepheus mosaics (32 and 40 panes with a RedCat+ASI1600), and only toward the NCP where curvature starts to become more of an issue. They don't detract from the image when viewed in a browser but it would be good to know exactly what has caused them - I would guess a stacking/registration problem but that is a pure guess - I don't really know - and why would you get such a thing on a single pane image?

I've been imaging this region myself recently and it is a real challenge to bring out the dust and maintain some colour in the Iris. Just looking at your image 1:1 (so no pixel peeping) these artefacts pop up in several places across the image - I am really not sure what is causing them because they don't look like hot pixels to me: - there are also a few orange/red artefacts - all the same sort of shape - very odd. These ASI2600MC cameras seem to be great for capturing dust - you've done a great job.

This is clever stuff Lee - the defaults in PI Image Solve & Annotate can be overwhelming! Another great job joining all four panes - seamless integration and a perfect background - to my eyes! Adrian

This is the really cool feature - updating almost in realtime. It was curiosity that led me to complete a PM alignment and then check it with SharpCap using the PM camera - confidently expecting it would spot on! Oh well - too much to hope for. I also then went on to check with the ASIair and I didn't score 10/10 for that either! Lesson learnt - stop fretting and get on imaging - I am a PoleMaster devotee.

Exactly my experience with a PoleMaster. I found the QHY camera is also recognised by SharpCap so you can use that as confirmation if you feel so inclined - but I would advise against it - and don't be tempted to triple check with an ASIair either! 🤣

The Iris, now with nine hours of data - not sure it worth investing more time - the law of diminishing returns is starting to kick in I fear: Time to focus on the ET and try to grab some more data before astro darkness is lost in about five weeks time. Thanks for looking. Adrian

Interesting to see what you've achieved - I am currently imaging the exact same thing and have amassed 150m of R, G and B and 90m of Lum - it's a challenge. I think I prefer your Medium Iris but your Bold dust/background. Adrian

Thank you Carole. Haha - I don't subscribe to UFOs. I'm currently reading the Foundation series which predicts a time when we populate the galaxy - a terrifying prospect. Adrian

Thanks Lee. RGB imaging is my nemesis - truth is I don't have a clue what I am doing so I don't do too much! Haha! You know me. I am a firm believer that space is dusty, dirty and dark with pockets of beauty - and dangerous, but not to us imagers - only our wallets! 😆

Nebula season might be drawing to a close but in the late hours of the evening NGC7023 rises above 30 degrees just after astro darkness begins, followed by IC1396 at around about 02.00. These two provide an interesting contrast for the SM90ED+ASI1600MM+8EFW to do first a bit of broadband imaging and then a bit of narrowband imaging. Here is six hours over two nights (two hours per RGB filter) on the NGC7023 ..... followed by six hours over two nights (two hours per 3nm narrowband filter) on IC1396. I have intentionally set out not to over process these images and intend to keep adding data until astro darkness runs out in May - clear (Moonless for the Iris) nights permitting. Captured with an ASIair, pre-processed in APP, post-processed in PI. Thanks for looking. Adrian

But it has got to have been worth the system disruption surely. What an unforgettable experience.

You probably don't want to hear this but I found I couldn't get a satisfactory collimation with the stock focuser unit - too much droop from the draw tube. I upgraded to a Baader DST and found collimation to be much easier and all done with a Baader laser collimator and a star test. I sold my RC purely cos' it was getting too much of a lift for my ageing hands - I was frightened to death I'd drop it one cold night. Like so many astro things I now regret selling as the images it produced when used with an ASI294MC (also sold ) were very good indeed.