Very large telescope observations of the peculiar globular cluster NGC 6712: Discovery of a UV, H alpha-excess star in the core

We present results from multiband observations in the central region of the cluster NGC 6712 with the ESO Very Large Telescope. Using high-resolution images we have identified three UV-excess stars. In particular, two of them are within the cluster core, a few arcseconds apart: the first object is s tar "S," which previous studies identified as the best candidate to the opt ical counterpart to the luminous X-ray source detected in this cluster. The other UV object shows clear-cut Ha! emission and, for this reason, is an a dditional promising interacting binary candidate (a quiescent low-mass X-ra y binary or a cataclysmic variable). The presence of two unrelated interact ing binary systems a few arcseconds apart in the core of this low-density c luster is somewhat surprising and supports the hypothesis that the (interna l) dynamical history of the cluster and/or the (external) interaction with the Galaxy might play a fundamental role in the formation of these peculiar objects.