by Craig and Tammy Temple
This globular cluster in Hercules is the finest in the northern hemisphere. Easily seen in dark skies with the naked eye, the magnitude 5.8 ball of stars contains over 400,000 members. Originally discovered by Edmund Halley, it was added in 1764 as the 13th entry in Messier's catalog. This 2 hour image was taken over two non-consecutive nights, May 7 and 17, 2009. The temperatures were 73° F & 54° F, respectively.
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Celestron C8 SCT with Celestron f/6.3 FR/FF
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Atlas EQ-G w/EQMOD, Guided
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Canon 350D (self-modified) w/Astronomik EOS Clip IR filter + 2" Hutech IDAS LPS filter
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24 x 300s @ ISO 400
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Captured/Calibrated/Registered/Stacked/Initial processing in ImagesPlus 3.80 beta
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Post processed in Photoshop CS4/Gradient XTerminator/Noise Ninja/Carboni's Tools.