Rockline position for the disks around different central stars. The thick black line indicates the disk contour at the gas density of 5 × 10³ cm^-3 for all our disk models, and we consider it as delimitation of our disk, because the erosion happens at more then 4 disk scale heights. The different colour and line styles delimit the contours of the disk with T_dust = 1500 K assumed as sublimation temperature of silicates. Upward and inward of this contour, the dust is sublimated, and the disk is truncated. It describes the effective extension of the disk according to the dust sublimation temperature. For late type stars, disk temperatures are too low, and the contour is replaced by a vertical line that indicates the distance from which the dust in thermal equilibrium should be photoevaporated. The position of the central star is indicated by the star symbol.