The distance to the young open cluster Westerlund 2

Abstract

Evidence is presented indicating that the young star cluster Westerlund~2 lies $d_{\odot}\sim3.0$ kpc in the direction of Carina. The distance is tied partly to new $UBVRI_c$ photometry and revised spectral classifications for cluster stars, which imply that dust in the direction of Carina is characterized by an anomalous extinction law ($R_V\sim3.8$). That result was determined from a multi-faceted approach relying on the variable-extinction and color excess methods.