A probable giant planet imaged in the ??Pictoris disk

Context. Since the discovery of its dusty disk in 1984, ??Pictoris has become the prototype of young early-type planetary systems, and there are now various indications that a massive Jovian planet is orbiting the star at ~10?AU. However, no planets have been detected around this star so?far.Aims. Our goal was to investigate the close environment of ??Pic, searching for planetary companion(s).Methods. Deep adaptive-optics L'-band images of ??Pic?were recorded using the NaCo instrument at the Very Large Telescope.Results. A faint point-like signal is detected at a projected distance of ?8?AU?from the star, within the northeastern extension of the dust disk. Various tests were made to rule out possible instrumental or atmospheric artefacts at a good confidence level. The probability of a foreground or background contaminant is extremely low, based in addition on the analysis of previous deep HST?images. Its L'=11.2 apparent magnitude would indicate a typical temperature of ~1500?K and a mass of ~8?MJup. If confirmed, it could explain the main morphological and dynamical peculiarities of the ??Pic?system. The present detection is unique among A-stars by the proximity of the resolved planet to its parent star. Its closeness and location inside the ??Pic?disk suggest a formation process by core accretion or disk instabilities rather than binary-like formation processes.