|M9: Globular Star Cluster (Ophiuchus) RA: 17h 19.2m / DEC: -18° 31'.0|
Instrument: 10-inch Starfinder
Ophiuchus is home to seven globular clusters in the Messier catalog. You'll find this example about 3.5 degrees south-southeast of 2.4 magnitude Sabik. M9 stands magnification quite well. The view at 129X in my 10-inch Newtonian reveals a salty core region populated by several 13th magnitude stars in a tightly knit group. The subtle outer halo doubles the apparent size of M9 to about 8 arc minutes. The four brighter stars due east of M9 range from 9th to 12th magnitude. Two neighboring globulars, NGC 6356 and 6342, are fine targets for moderate aperture. M9's integrated visual magnitude is 7.8.
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Revised: February 15, 2002 [WDF]