M13: Great Hercules Cluster

RA: 16hrs 41min 42sec   Dec: 36 28'     Mag: 5.7   Distance: 22500 light years   Constellation: Hercules

Also designated NGC6205, this great globular cluster in Hercules is a great summer object to observe.  First noted in 1714 by Edmund Halley and catalogued by Messier in 1764, it was only first understood to be a stellar cluster by William Herschel in the 1780s.  With the meagre resolving power of my 8" LX90, the picture I've taken is nothing like the huge gossamer bauble of bluish stars that you see in professional photographs, it's still worth displaying the northern hemisphere's best star cluster as I caught it with the DSI at f10 on the night of the 6th August 2007.  The moon was in its final quarter and the temperature was 15C

Processing for this picture was extremely simple.  Two final photographs were combined from a 90x8minute and 80x8minute stacks made by the Meade DSI and the AutoStar Envisage software.  White and black points were set in the individual R, G, and B, channels, with very little midtone enhancement, using the RGB channel together in the curves command.

 

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