DUST DEPLETION IN THE INNER DISK OF BETA-PICTORIS AS A POSSIBLE INDICATOR OF PLANETS

IT is not yet possible to see planets orbiting other stars, although t his may soon change as observing methods improve(1). Indirect evidence for the presence of circumstellar dust disks out of which planets cou ld form has been obtained for several stars, in the form of excess inf rared emission, presumed to be from the hot dust(2,3). Planets orbitin g in such dust disks would be expected to sweep out dust-free tracks(4 ). Indirect evidence for dust-free regions has been reported(5-9), bas ed on an analysis of the spectral energy distribution, but the interpr etation of the observation is not unique(7,9). Here we present an infr ared image of the inner dust disk of the star beta Pictoris with a lin ear resolution of 5 astronomical units (AU), equivalent to the distanc e from the Sun to Jupiter. We find that the dust is asymmetrically dis tributed and is clearly depleted within 40 AU Of the star, which we in terpret as indicating the possible presence of at least one planetary body orbiting beta Pictoris.