#1  
Old 01-07-2005, 07:42 AM
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iceman (Mike)
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July Challenge Object - M22

Hi all.

We'd love you to take part in the July Observing Challenge. Please post your observing reports and sketches for M22 in this thread. Discussions about the object can also be in this thread.

Please ensure scanned sketches obey the image posting guidelines when you attach them.

For deep-space images of the object, see the "Deep Space" astrophotography forum.
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  #2  
Old 01-07-2005, 02:03 PM
dhumpie
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This is one of the best globulars for small telescopes and it definately better than the great northern globular M13 (best it both in size, brightness and resolution). It is easy to find as it is located just to the left of the top of the triangle that forms the lid of the teapot and it is bright. My bet is for it to be visible from semi dark observing locations as it is about magnitude 5. It is also very very easy to resolve as it is a class III globular (from memory). Even my 15x70's shows some of its numerous suns when tripod mounted. It is fully resolved above 100x in my old 76mm f/9 newt and my Orion 80ST. The views are nothing short of jawdropping in a 6" scope at similar powers. At low power I see spidery legs extending from its core (see my sketch). At 300x in the 6", it appears very similar to Omega Centauri in that it looks more like an open cluster than a globular as this globular does not contain a condensed core. To me, this is one of the globulars that has more character due to its spidery legs. The other one is the starfish cluster in Pavo (NGC 6752). O'Meara nicknamed this the crackerjack cluster. See my sketch at:

http://www.geocities.com/dhumpie/dastro/m22.jpg

Darren

Last edited by dhumpie; 01-07-2005 at 05:18 PM.
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  #3  
Old 11-07-2005, 06:20 AM
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CosMos (Rich)
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Referring to my observing notes, one of the best views of M22 occurred on the evening of 25 July 1990 with a 20cm f6.7 dobsonian reflector from the light polluted sky of Mt Eden. Employing an eyepiece of low power (48x), M22 appeared as a large and very bright irregular cluster with chains of bright stars radiating outwards to the southwest. A step up in power to 90x magnification showed “fingers” of bright stars overlaid upon a milky-white background of fainter unresolved stars, giving this cluster an obvious 3-D effect. Further observations over the years have not dimmed my enthusiasm for this cluster, truly one of the best of its type available to telescopes.

NGC 6642 is another globular cluster lying around 1° to the northwest of M22. Discovered by William Herschel on August 7, 1784; “globular, pB, R, gpmbM, 2', resolved into visible but vS stars 15..16m”, NGC 6642 appears as a small and faint irregularly round glow, unimpressive to the eye. Large apertures will show brightening toward the central region and a prominent stellar nucleus.

Rich
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  #4  
Old 11-07-2005, 06:53 PM
dhumpie
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Nice report Rich! Come on people where are the rest of you ))))

Darren
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Old 11-07-2005, 11:33 PM
ausastronomer (John Bambury)
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Quote:
Originally Posted by dhumpie
Nice report Rich! Come on people where are the rest of you ))))

Darren

Darren,

I have to agree with your comment, apart from yourself and Rich and a few others, very few people seem to take much interest in the monthly observing challenges which actually take quite a bit of time to write up. It also takes Andrew quite a bit of time to do the finder charts. Sometimes I ask myself is it worth the time I spend writing up some of the commentaries. We figured it would take a couple of months for people to become involved, but we have now been doing this 3 months with barely a yelp.

CS-John B
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  #6  
Old 11-07-2005, 11:40 PM
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[1ponders] (Paul)
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Great reports Rich and Darren. Flipping back and forward between your reports and the images really helps me to appreciate what I'm seeing in the images.
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  #7  
Old 12-07-2005, 06:24 AM
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iceman (Mike)
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Quote:
We figured it would take a couple of months for people to become involved, but we have now been doing this 3 months with barely a yelp.
I agree John, but I'm hoping it's just a case of people not submitting the reports/sketches, but hopefully they are still getting out and observing these fine objects.

At least the DSO photographers are contributing with some great images.

C'mon guys get into it!
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Old 12-07-2005, 12:21 PM
dhumpie
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I agree. It does not take much to just write a line or two about your observing session. You don't need to sketch if it is too much work....come on guys...

Darren
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  #9  
Old 24-07-2005, 04:08 PM
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asimov (John)
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Iv'e been holding this back for awhile.. Sketched at the beginning of the month..

No report from me, other than to say the best globular, rivalled only by Omega Centauri!
Attached Thumbnails
Click for full-size image (glob.jpg)
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  #10  
Old 24-07-2005, 06:23 PM
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seeker372011 (Narayan)
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That's a sketch? not a photograph? Holy WOW!

and top observing skills too..
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Old 24-07-2005, 07:26 PM
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asimov (John)
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ummm..I didn't think it was all that great?? But thank you anyhow.
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Old 24-07-2005, 11:56 PM
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astro_south (Andrew)
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Nice sketch John - inspiring me to put a bit more effort in
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Old 25-07-2005, 12:47 PM
dhumpie
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Very nice John. How long did you take to do it...a couple of days or weeks

Darren
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Old 25-07-2005, 01:00 PM
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ving (David)
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thats not a sketch... its a work of art!
i'd settle for 1/100 of the talent!
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Old 25-07-2005, 04:07 PM
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asimov (John)
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Now receiving treatment for carpal-tunnel AND RSI lol Thanks for the great comments guys, Yep! it was meant to inspire you lol...I want to sketch the other 5 but I wanna sketch at the EP. This weather wont let me! I could 'cheat' & just pull up a pick from somewhere & sketch it I guess? Naa! that's unethical for me to do.

Oh....& nice reporting there, the rest of U guys!

Last edited by asimov; 25-07-2005 at 04:12 PM.
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  #16  
Old 31-07-2005, 09:24 AM
stringscope (Ian)
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I spent quite some this on M22 last night. Seeing was 6/10 with reasonable transparency. I used our old solid tube 8" F6 Dob with a variety of eyepieces.

This is the first time I have really taken the time to look at this object in detail. It really is a wonderfull GC.

I initially used a 2" GSO 30mm SV @ 38X (it is actually 32mm by measurement). In this eyepiece it was a large, bright circular haze with many superimposed stars. There were hints of tendrills or arms radiating outwards and the resolved stars seemend to be following these. A 20mm Synta Wide Field followed @ 64X. I now found the bright background haze starting to resolve into stars, but what really got my attention were the radiating tendrills or arms. These became very noticeable. The brighter stars formed long chains, particularly along the arms and the whole effect was very pretty. I decided to increase the magnification to 81X using a 15mm Ross wide angle binocular eyepiece (I think it is an Erfle). I felt this mag/fov best framed M22. I was able to resolve stars deeper into the cluster and the star chains and associated arms were really stunning. I spent some considerable time just looking and pondering what this object would look like up close in 3D. Before I moved on, just for fun, I pushed the magnification up using 9 and 6 mm Synta Wide Fields (135X & 203X). At these magnifications the level of resolution just kept on increasing although the arms and tendrills started to loose their impact.

Overall a beautifull sight and well worth spending some time on.
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Old 31-07-2005, 09:48 AM
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astro_south (Andrew)
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Great report Ian. It is nice how changes in magnification can change an object's appearence and there is usually a sweet spot given the conditions where the object appears the "best". Great to see you (and other people) spend some time and explore the magnifications.

If you love the effectiveness of radiating arms of stars make sure you check out the Pavo Glob (NGC 6752) - its nickednamed "the Starfish" for obvious reasons. It has a dense core and is really effective in smaller scopes and at meduim to low power - though don't be discouraged to push the power up and check out the condensed core.
(this glob will feature in an upcoming MOC )
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