Inner Rim of a Molecular Disk Spatially Resolved in Infrared CO Emission Lines

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

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