M10 - Globular Cluster

M10 - August 27, 2016
EdgeHD 11 with Hyperstar - 10x180sec QHY10 Camera

Finally got around to processing some of deep space objects (DSOs) I imaged back in August. Here is the globular cluster M10 (with the orange star 30 Oph to the left).  Since I'm having some problems with guiding at larger focal lengths (possibly a defect in my mount motor) I had to use the wide field Hyperstar setup and so the cluster is smaller than I could have gotten at the f/7 focal length.

M10 (also designated NGC 6254) is a globular cluster of stars in the equatorial constellation of Ophiuchus. The object was discovered by the French astronomer Charles Messier on May 29, 1764, who cataloged it as number 10 in his catalogue and described it as a "nebula without stars". In 1774, German astronomer Johann Elert Bode likewise called it a "nebulous patch without stars; very pale". Using larger instrumentation, German-born astronomer William Herschel was able to resolve the cluster into its individual members. He described it as a "beautiful cluster of extremely compressed stars". William Parsons, 3rd Earl of Rosse thought he could distinguish a dark lane through part of the cluster. The first to estimate the distance to the cluster was Harlow Shapley, although his derivation of 33,000 light years was much further than the modern value of 14300 LY.  (Wikipedia)