By Dave Fuller on 8/18/2014 7:26 AM
IC 4756: A huge, star-rich object

It's always interesting researching objects that are not Messiers or well-known NGC objects. Particularly with IC objects, the data available is, sadly, even harder to come by. But we need not know the nitty gritty details (IC 4756 has 6 blue stragglers!) to find and appreciate these clusters. No, what we need most often is simply knowing they exist, that they are easily seen, and worth finding/observing.

Star hop to IC4756 in OphiuchusI often find NGC objects that appear "bright" on Stellarium or on other lists that indicate a bright overall combined magnitude, but then when I see the size of the object, I have to roll my eyes sometimes. "A cluster just 10 arc seconds across? That's like looking at MARS!" (which, if you don't already know, looks incredibly tiny at the eyepiece). So when I saw an object that lists an angular diameter of 52 arc minutes (almost twice is large as the Moon) AND an integrated magnitude of 5.00, I knew I had to investigate further. 

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The Nightlight

This blog includes what to see in the night and daytime skies, thoughts on telescopes, binoculars, and other astronomy observing accessories and equipment, plus my own occasional notes on objects I've seen and observed. Oh, and the random theater or other "my take on life" post. In other words, there is always something interesting. Check it out.