IC 342

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Pete
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IC 342

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Tuesday, 2 Jan 2024 - The moon is down

Are my ongoing “light infringement” problems associated with moonlight? I’ve explored everything else. So following up on my Dec 20th log, I’m out on a pristine dark transparent calm moonless night. Maybe Bortle 4.5? And the holiday lights are gone so the horizon’s dark every direction.

No good wide-field targets so the camera’s moved from the refractor to the SCT. Camera refocused and new illuminated panel flat taken. Even with dark neighborhood the lower shutter is installed and the observatory is completely darkened – even shutting the monitor off.

I’ve worked galaxy IC 342 many times and have never been satisfied with the result as there are some very dim areas I’ve been unable to capture.
IC 342 240102 try 88 s.jpg
IC 342 240102 try 88 s.jpg (942.47 KiB) Viewed 24783 times
Galaxy IC 342
2 Jan 2024 18:18 – 22:22 hrs.
82 X 3 min, unbinned, -15°C cooling, 200 gain, 2 Hz guide rate
14” Meade LX200 GPS @ f/6.3 with unfiltered ASI2600MC-P camera

OK. This is my best IC 342 yet. Took a lot of tricky processing and that may be one of the reasons. But the field was uniformly dark!!! And that makes all the difference in the world when stretching an image.

Conclusions & lessons learned:

Obviously moonlight has been the problem. And maybe local lighting too. This is going to limit my imaging but lower the frustration level.

It was below freezing all-session and once the scope was setup and imaging initiated everything was monitored from the house using Windows Remote. Just not happy with that level of cold anymore.

hgp 1/3/24
Pete P.
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mark.m
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Joined: Fri Feb 03, 2017 1:13 pm

Re: IC 342

Unread post by mark.m »

Pete:
Nice job on a really challenging target...

Your experience with moonlight and other sky background glow is strongly confirming my own experience that getting good flats can be really hard. Further, it's difficult to "debug" the process of making and applying flats, so that when the results aren't what you were hoping for, it can be head-scratching to try and figure out what to do differently the next time.

- Mark
Mark M, AJ1B
Portsmouth, RI
Celestron 14" and Meade 10" SCTs
QHY268M + SBIG ST-9
GM2000 (10Micron)
American Association of Variable Star Observers (AAVSO) observer code: MMU
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Pete
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Re: IC 342

Unread post by Pete »

Actually, the flats are under control. Turns out they weren't the problem.

This is a tough object indeed. The outer zone is VERY faint. Different zones processed with PS's lasso tool. Working LRGB instead of OSC would make a big improvement.

Don't understand how moonlight causes the problem but perhaps it's enough to know that it does.
Pete P.
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menardre
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Re: IC 342

Unread post by menardre »

Pete

Like you, I have imaged IC 342 a few times. Your latest version was really well done.

I am always amazed at the images from your 14 inch Meade... I have a difficult time with my 11 inch Celestron (and even then I use a 0.7 focal reducer). Working at the FL of your system really is a challenge with very little room for error.

Roger
Roger M.
Celestron CPC1100 EDGE, Stellarvue 130T refractor dual mounted on iOptron CEM120 on permanent pier mounted in Observatory. Imaging camera ZWO ASI2600 OSC, guide camera Lodestar or ZWO ASI290MM.
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