We present high-resolution infrared spectroscopy of the Herbig Ae star HDÂ 141569Â A in the COÂ v = 2 - 1 transition .
With the angular resolution attained by the adaptive optics system , the gas disk around HDÂ 141569Â A is spatially resolved down to its inner-rim truncation .
The size of the inner clearing is 11 \pm 2Â AU in radius , close to the gravitational radius of the star .
The rough coincidence to the gravitational radius indicates that the viscous accretion working together with the photoevaporation by the stellar radiation has cleared the inner part of the disk .