Messier 10 (also M10, NGC 6254 and GCl-49) is a magnitude +6.4 globular star cluster located 14300 light-years away in the constellation Ophiuchus. The cluster is positioned about 3 degrees to the south-west of Messier 12. The cluster belongs to class VII in stellar density in the Harlow Shapley and Helen Sawyer Hogg classification system, where clusters of class I are denser and Class XII are less dense. The cluster was discovered by French astronomer Charles-Joseph Messier on the 29th May 1764.
Right Ascension 16h 57m 8.92s, Declination -04° 05' 58.07"
Title: UV observations of the globular cluster M10 from HST and GALEX. The BSS population Authors: E. Dalessandro, F. R. Ferraro, B. Lanzoni, R. P. Schiavon, R. W. O'Connell, G. Beccari
We present a combination of high-resolution Hubble Space Telescope and wide-field ground-based and Galaxy Evolution Explorer data of the Galactic Globular Cluster M10 (NGC6254). By using this large data-set we determined the center of gravity of the cluster and we built its density profile from star counts over its entire radial extension. We find that the density profile is well reproduced by a single-mass King model with structural parameters c=1.41 and r_c=41". We also studied the Blue Straggler Star population and its radial distribution. We count a total number of 120 BSS within the tidal radius. Their radial distribution is bimodal: highly peaked in the cluster center, decreasing at intermediate distances and rising again outwards. We discuss these results in the context of the dynamical clock scheme presented by Ferraro et al. (2012) and of recent results about the radial distribution of binary systems in this cluster.