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A Question for Those Who Observe with Smaller Tele

Started by markvcostello3, 08/16/2011 02:04PM
Posted 08/16/2011 02:04PM Opening Post
I'd like to throw this out for those of y'all who spend a fair amount of time observing with telescopes 6" or smaller. Last night, I spent maybe an hour, hour and a half in Ophiuchus, divided about equally between Globulars M10 and M12. Observing both with a 5" refractor, at times it seemed that there was a thin spray of stars that could be seen across the face of each, particularly at 206X. Also, at both 103X and 206X, it seemed that I could see a spray of stars around them. The background material on these clusters indicate that they are a bit loose for globulars. So I wasn't too surprised to see some individual stars in and near them. But I thought I'd ask: Has anyone gotten this type of partial resolution (or better) with a telescope of similar size?

Thanks very much.

Mark Costello
Matthews, NC, USA

"I hear you're mechanically inclined. Did you ever do anything with perpetual motion?"

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Posted 08/17/2011 02:50AM #1
Mark Costello III said:

I'd like to throw this out for those of y'all who spend a fair amount of time observing with telescopes 6" or smaller. Last night, I spent maybe an hour, hour and a half in Ophiuchus, divided about equally between Globulars M10 and M12. Observing both with a 5" refractor, at times it seemed that there was a thin spray of stars that could be seen across the face of each, particularly at 206X. Also, at both 103X and 206X, it seemed that I could see a spray of stars around them. The background material on these clusters indicate that they are a bit loose for globulars. So I wasn't too surprised to see some individual stars in and near them. But I thought I'd ask: Has anyone gotten this type of partial resolution (or better) with a telescope of similar size?

Thanks very much.

I get fairly good resolution of both globulars with my 5-inch MCT...when it's dark and they are decently high.

Uncle Rod

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Posted 08/24/2011 11:20AM #2
Hi Mark,

Not sure about those two particular globs, but in general with most of the Messier globs I view with my 4" refractor I can see what you describe. What is critical though is that it be fairly dark evening, and also critical that your eyes are dark adapted well. On many evenings I can start the night viewing some globs and not very satisfying, but then later in the observing session with my eyes now well dark adapted, as I come back to the same globs for second looks, they are quite detailed and granular. So proper dark adaptation with smaller scopes IMO is critical for these finely detailed targets.

-Bill
Posted 08/24/2011 11:50PM #3
Just tried these clusters at 150X in a 3" reflector. Averting my eyes brought out what appeared to be the twinkle of individual stars, but I could not see them with direct sight. Thanks for pointing out these globulars before they start sinking into the dusk. smile