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Messier 107

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#1 Madratter

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Posted 05 June 2020 - 07:55 PM

I have been trying to pick off some of the numerous globular clusters that I have not imaged after finishing with my main object. Messier 107 was on my list and relatively accessible at only around -13 declination.

 

get.jpg?insecure

 

I know I will probably get some disbelief when I say this but I used no saturation whatsoever on this image. The strong colors are a combination of using relatively short exposures for my camera and my telescopes f-ratio (f/8), along with careful processing of the color information (arcsinhStretch).

 

The image is 9 exposures of 5 minutes each of R, G, and B.

 

The incredibly red star is not an artifact. It is in fact a variable star, probably very near its minimum. It is V720 Oph and is a long period variable with a period of roughly 332 days similar to Mira (StarTools 4 Imaging). It has a B-V of 2.571 (SkyTools 4 again) that is very very red.

 

As usual make sure to click the image below to see it properly (full size).

 

M107 20200531 v01 1024x769.jpg

 

Equipment:

Telescope: AT8RC at f/8

Camera: SBIG STF-8300m

Mount: Paramount MyT

Guide Scope through OAG: QHY5LII-m

Acquisition Software: Voyager

Processing: PixInsight


Edited by Madratter, 05 June 2020 - 08:09 PM.

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#2 sunnyday

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Posted 05 June 2020 - 08:00 PM

very nice shot .

pin points stars . thanks , well done .


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#3 klaussius

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Posted 05 June 2020 - 08:22 PM

The incredibly red star is not an artifact. It is in fact a variable star, probably very near its minimum. It is V720 Oph and is a long period variable with a period of roughly 332 days similar to Mira (StarTools 4 Imaging). It has a B-V of 2.571 (SkyTools 4 again) that is very very red.

That star caught my eye as well. I actually zoomed in to make sure it wasn't a hot pixel (I knew it wouldn't be but I was in disbelief).

 

I've found a couple of such shockingly red stars in some of my images, but I never get used to that. They're unreal.


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#4 Dave Mitsky

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Posted 05 June 2020 - 08:44 PM

There are quite a few carbon stars that are very colorful, some of them are deep red.

https://skyandtelesc...-red1203201401/

https://astronomy.co...ddest_stars.pdf

 

https://www.go-astro...arbon-stars.php


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#5 Madratter

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Posted 06 June 2020 - 07:30 AM

Thank you for the nice comments and the likes. :)

 

In terms of the red star, I was curious what the B-V of Betelgeuse was simply because that is one of the more strongly colored stars we see with the naked eye. It has a B-V of +1.85 so the star above is signficantly cooler and redder than that. And don't forget that our eye is not particularly good at seeing longer wavelengths of red, while mono cameras do so quite well.




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