M 101

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Stefan B
Posts: 422
Joined: Sat Oct 31, 2020 8:59 pm

M 101

Post by Stefan B »

Finally here's a new image... M 101 framed by three fainter galaxies:

Image

It's 18 hours which sounds like a lot but only six of them are broadband. But there were no clear skies during new moon. Instead there were two clear nights with a moon brighter than 60%. And since I started the project in February and there won' t be clear skies before moon is over 60 or 70% again, I'll call it a day and move on to other objects...

Since I tried to let the data guide me and there's a more Ha data than broadband, the HII regions are emphasized quite a bit by NBaccent.

Hope you see more stars than me ;)

Regards
Stefan

PS. Fot details see https://www.astrobin.com/67hrdy/
Last edited by Stefan B on Mon Apr 24, 2023 6:29 am, edited 1 time in total.
fmeireso
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Location: Belgium

Re: M 101

Post by fmeireso »

That is really very nice, Stefan. Bit stronge saturation, but the HII regions are exquisit and very well pronounced :thumbsup:
Stefan B
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Joined: Sat Oct 31, 2020 8:59 pm

Re: M 101

Post by Stefan B »

Thanks, Freddy. You're right about the saturation but I just tend to overdo that :lol:
decay
Posts: 433
Joined: Sat Apr 10, 2021 12:28 pm
Location: Germany, NRW

Re: M 101

Post by decay »

Hi Stefan,

a fireworks of colours :) :thumbsup: And I too like the HII regions. They make this galaxy much more worth seeing.
The larger stars seem to be a bit oblong? Is this due to the problems with collimation you described last time? :think:

I had the same idea as you, but I was less lucky. This galaxy is not my friend :( . On my first session on M101 I missed the focus postion and I had to discard it completely. The next session the focus position was fine, but seeing was poor and I noticed a bit of walking noise that I had never seen before in my images. But the outcome is the 'best' (haha) I have had with M101 so far, tough. My intention was to do another session in order to get some Ha data, but no stars for me either :cry: :confusion-shrug:

Best regards, Dietmar.
Stefan B
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Joined: Sat Oct 31, 2020 8:59 pm

Re: M 101

Post by Stefan B »

I know what you mean, Dietmar :mrgreen: But don't know what that is. I had the impression that my collimation was okay this time. Guiding seemed good, too. No tilt that's very prominent.

But to me bigger stars don't appear egg shaped but rather rectangular. I usually don't see that in my images. Except for an image of the exact same galaxy from two years ago: https://www.astrobin.com/iuea9a/C/

Maybe it's something in the FOV...maybe these aren't stars but Borg cubes pretending to be stars. I also had the impression that the phenomenon can be seen on more stars now compared to the old image. Maybe the Borg are colonizing the area :think:

Or it's just me not knowing what I am doing in terms of acquisition and processing :lol:

But you're right, M 101 is not an easy target. Lots of faint stuff in the arms, high dynamic range. And conditions aren't easy at the moment, too, as you said. So let's hope for more clear skies during the coming new moon :thumbsup:

Good luck!

Stefan
Mike in Rancho
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Re: M 101

Post by Mike in Rancho »

Nice one Stefan. Lots of nebula knots there. 18 hours, wow. :shock:

I guess there is a bit of cuboid aka Borg action going on. I wonder what that is. Of course, resistance is....

Overall background strikes me as leaning too magenta, or red. Did you reverse the remainder of the field after NB Accent? Any use of SS? I'm thinking maybe not, and especially not Isolate, as I see quite a busy amount of tiny stars. That said, sometimes if I do use Isolate I will modify it to process both, rather than lum only, which can help with that sort of thing. Dimsmall I believe is already both.
Stefan B
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Re: M 101

Post by Stefan B »

Thanks, Mike!
Mike in Rancho wrote: Wed Apr 26, 2023 7:09 am 18 hours, wow. :shock:
Yeah, with 18 hrs I would have hoped for a better result but AP is a humbling experience, isn't it? ;) And remember, 12 hrs are for the knots only. Finding NB targets for the bright moon phases during galaxy season isn't easy, so why not waste two nights on it? :)
Mike in Rancho wrote: Wed Apr 26, 2023 7:09 am Overall background strikes me as leaning too magenta, or red.
Really? Haven't noticed this until now. On none of the screens I've looked at it. But probably not very good screens... To me the background is pretty black and neutral. On the other hand looking at the histogram on astrobin the channels don't look very well aligned (sorry don't have access to my PC with Photoshop - so the AB histogram will have to do):

Image

So if the red channel is shifted towards the right, the background might have a red touch. But shouldn't then the whole image be too red? Overall the galaxy and the stars look okay balanced to me. What do you think?
Mike in Rancho wrote: Wed Apr 26, 2023 7:09 am Did you reverse the remainder of the field after NB Accent?
Yes, otherwise all the stars would have been too red. So I masked out the galaxy and undid the NBAccent via layer.
Mike in Rancho wrote: Wed Apr 26, 2023 7:09 am Any use of SS? I'm thinking maybe not, and especially not Isolate, as I see quite a busy amount of tiny stars. That said, sometimes if I do use Isolate I will modify it to process both, rather than lum only, which can help with that sort of thing. Dimsmall I believe is already both.
I didn't use Isolate (I don't use that in general). But DimSmall (about 60% strength) and Saturate (about 100-120% saturation) were used. Could that be the reason!?

Thanks for pointing that out, Mike!

Regards
Stefan
Mike in Rancho
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Re: M 101

Post by Mike in Rancho »

Interesting, Stefan. Well, if you did the proper reversal after NBA, reversing all but the target galaxy with its knots, then I would lean towards the Color module. Might be balanced a wee bit towards the red, and/or, a strong setting in dark saturation is making it stand out. :think:
Stefan B
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Re: M 101

Post by Stefan B »

As so nicely put in another thread, here's just another M 101 before/after the supernova. But since I imaged M 101 in April I had no other choice than to image it once again with SN2023ixf. Here's an animation of it:

M101-supernova-animated-crop.gif
M101-supernova-animated-crop.gif (637.88 KiB) Viewed 1443 times

I gathered another 6 hours of broadband data and combined it with my NB data from April. Additionally I processed the old broadband + NB data from scratch in order to match the processing of the new data. Only partly successful. Anyway I think it's pretty cool to see something new appear in the unchanging heavens ;)

I'll probably throw all the data together just as Mike did and see what it looks like. But not today...

CS
Stefan
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