PR-drag pile-up scenario: grain evolution as a function of initial grain size for three different stellar types and two grain compositions. Left panels: grain size as a function of stellar distance. The arrows denote the temporal evolution. The dash-dotted line is the sublimation distance as a function of grain size, while the vertical dashed line indicates the position of the parent bodies. The gray horizontal zone identifies the range of grains with β > 1, and the horizontal dotted lines correspond to β = 0.5 (see also Fig. 1). Right panels: eccentricity as a function of semi-major axis. The horizontal plain line represents the e = 1 limit beyond which particles are on unbound orbits. For both the left and right panels, the left yellow area corresponds to the physical location of the star and the arrows denote the evolution way.