* Astronomy

Title: BS196: an old star cluster far from the SMC main body
Authors: E. Bica, J. F. C. Santos Jr., A. A. Schmidt

We present B and V photometry of the outlying SMC star cluster BS196 with the 4.1-m SOAR telescope. The photometry is deep (to V~25) showing ~3 mag below the cluster turnoff point (TO) at Mv=2.5 (1.03 Msun). The cluster is located at the SMC distance. The CMD and isochrone fittings provide a cluster age of 5.0±0.5 Gyr, indicating that this is one of the 12 oldest clusters so far detected in the SMC. The estimated metallicity is [Fe/H]=-1.68±0.10. The structural analysis gives by means of King profile fittings a core radius Rc=8.7±1.1 arcsec (2.66±0.14 pc) and a tidal radius Rt=69.4±1.7 arcsec (21.2±1.2 pc). BS196 is rather loose with a concentration parameter c=0.90. With Mv=-1.89±0.39, BS196 belongs to the class of intrinsically fainter SMC clusters, as compared to the well-known populous ones, which starts to be explored.

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