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M13 Hercules Globular Cluster
VAO, Webster NY
FWHM 2.2", 1x1 bin, 0.54 "/pix
12" Meade SCT
© Billy Vazquez |
M13, the Hercules Globular Cluster was discovered by Edmund Halley in 1714 and catalogued by Charles Messier on 1764. This cluster at an apparent magnitude of 6 contains about a million stars on an approximate sphere spanning 150 light years. The image is a composite of 5x1 minute exposures unguided at f/6 on the VAO's 12" Meade to test the new Paramount MX mount. Close inspection of the stars show a small drift of about 2 arc seconds per minute. This is likely due to a non accurate PEC correction. Still nothing to be sniffed at a plate scale of 0.54"/pixel. The seeing was transparent and steady on July 29th, 2012 the reported FWHM was 2.2"
