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[RCC] M81 and neighbors

Request for feedback M81 Galaxy Deep Sky Messier Objects
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Chris Eplett avatar
Chris Eplett avatar
New to the hobby, started out last October.

I'm shooting from a white zone, so I find I've been struggling capturing broadband targets and eliminating light pollution artifacts. I've also struggled pulling details out of galaxies. I find it much easier to process nebulae, honestly.

Last night I shot 5 hours on the M81 group, and came up with this: https://www.astrobin.com/i39mm2/

This was shot with *no* filter (despite being Bortle 8-9 and a nearly full moon), but I think I was able to eliminate *most* of the pollution artifacts. There's still a band between M81 and NGC 3077 that I could quite eliminate with GraXpert.

Additionally I'm not entirely pleased with how I was able to pull out detail from the galaxies themselves.

I understand I probably need to get quite a bit more time on these targets.

I'd appreciate any pointers on how to better handle background extraction, and how to pull out detail in galaxies.

Thanks,
Chris
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kurt ragsdale avatar
kurt ragsdale avatar
It looks good but nothing beats out a good dark sky site for observing or astrophotography. See if you can find a darker sky site that you will be able to use and feel comfortable using if you can find one because it will make a difference.
Alan Brunelle avatar
Alan Brunelle avatar
I think it looks quite nice, considering where you are shooting from.  These galaxies are not really faint subjects, so astrophotography-wise galaxies such as this grouping are decent targets for your situation.   However, as you will see on a good number of posts on AB, there is a lot of other stuff going on in this field that you won't be able to capture from your area.  That includes some faint IFN and some low surface brightness galaxies and star streams.  Also, your image is somewhat limited to the brighter parts of the spiral arms.  In some respects that is nice because it highlights those arms.  Some prefer to boost the star halo between the arms and around M81 to such an extent as to make the axes of the spiral arms almost disappear.  

It is always said that we need more exposure time on our subjects.  Your optic seems like it has a decent speed and 5 hours seems like a decent time for this field.  I am not sure how much time you want to spend on this field.  You might not get the reward for the effort.

I did not see that you used a light pollution filter.  Given your location, that might gain you a decent advantage.  Find one that is suitable for broadband targets if it is galaxies you want to shoot.
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Oskari Nikkinen avatar
Oskari Nikkinen avatar
You need signal to noise ratio, and to get it you need to pump up the integration. Unfortunately for you in a white zone it means you gotta go for dozens of hours more to get a reasonably more deep image. Nothing particularly wrong about the image, other than it is still very short and shallow - just an unfortunate reality under light polluted skies.

You should consider traveling outside your city with the kit if you really want to get the best out of broadband targets. Every magnitude of brightness darker makes capturing signal to noise ratio roughly 2.5 times faster. If you are in an SQM 18.0 location, then by traveling to SQM 20.0 skies you would get in effect 6 hours worth of data in 1 hour (rather easy to find, almost everywhere on Earth there is a spot like this within a reasonable drive away).

I do that with my imaging, i realized that by driving an hour, imaging an hour, driving back an hour i get a better image than spending the entire night at home under bortle 8 light pollution.
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