POX 186: the ultracompact blue compact dwarf galaxy reveals its nature

High resolution, ground based R and I band observations of the ultra compac t dwarf galaxy POX 186 are presented. The data, obtained with the ESO New T echnology Telescope (NTT), are analyzed using a new deconvolution algorithm which allows one to resolve the innermost regions of this stellar-like obj ect into three Super-Star Clusters (SSC). Upper limits to both masses (MN 1 0(5) Mg) and physical sizes (less than or equal to 60pc) of the SSCs are se t. In addition, and maybe most importantly, extended light emission underly ing the compact star-forming region is clearly detected in both bands. The R - I color rules out nebular Ha: contamination and is consistent with an o ld stellar population. This casts doubt on the hypothesis that Blue Compact Dwarf Galaxies (BCDG) are young galaxies.