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Open cluster sketch, 8/13/09

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#1 NerfMonkey


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Posted 14 August 2009 - 02:36 PM

Hey everybody, I did this sketch of one of my favorite open clusters last night and thought I'd post it here. Instead of telling you what it is I'd like to see if anyone can identify it. It will probably be difficult since the positions and brightnesses of the stars aren't completely accurate. The sketch took me an hour to do, from about 1:55-2:55 AM GMT, 8/14/09. I used a 12" f/5 Dob with a 23mm Axiom LX, giving me about 65x and a 1.3° FOV.

-It's not a Messier.
-It was a little past culmination when I sketched it.
-It was south of the zenith from my location at 41° N.

The directions might be hard to see (I had to draw them in with MS Paint) but north is up and east is to the left.

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Let me know what you think, and don't be afraid to throw out a guess even if it's completely random.

#2 Starobserver


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Posted 14 August 2009 - 02:46 PM

Hi Mike,

Could it be NGC 6940?

#3 NerfMonkey


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Posted 14 August 2009 - 04:28 PM

Good guess but not the right cluster. This one's south of 6940.

I've switched out the poorly done invert for a better one but apparently editing pictures in GIMP triples the file size so I had to link to it instead.

#4 NerfMonkey


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Posted 15 August 2009 - 10:30 AM

Sorry for the double post but since nobody else is guessing, here's the answer.

NGC 6633 in Ophiuchus. I've always loved this one because the brightest stars form a chain running nearly east to west and their beautiful blue colors. It's also in the same area as a couple of other wonderful open clusters, IC 4665 and IC 4756.

Supposedly it is a naked eye cluster in a dark enough sky but in my mag 5 back yard it's just barely visible in my 8x50 finder scope. Still a nice sight in large binoculars though.

#5 JayinUT


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Posted 15 August 2009 - 12:23 PM


Next time I'm out I will have to take a look at this OC as its on the Best of the NGC. It looks like you really captured the various chains of stars here. Nicely done and thanks for the prep!

#6 frank5817



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Posted 15 August 2009 - 03:39 PM


Nice sketch. :bow: :cool: I struggled with this one for a while and then gave up. I have observed this one but never sketched it.

Frank :)

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