Maximum geometrical optical depth as a function of distance to the star (Eq. (5)). The profiles are derived from the analytical model of Wyatt (2005), in which dust is produced by a source at radius r₀ and subsequently migrates inward due to P–R drag, while suffering destruction from mutual collisions. The solid lines correspond to solar-mass stars, the dashed lines to 2 M_⊙ stars. Profiles for different parent belt locations are shown in different colors. All profiles assume dust grains with β = 0.5.