Matter development in the DPS after a fly-by shown for the typical case of a 20 AU periastron distance. The stars were of equal mass, and the orbit was parabolic and coplanar. The colour indicates the eccentricity after the fly-by. The position of the matter corresponds to that if the star would have remained unperturbed, but at the time of periastron passage. Panel a: particle development in the entire disc. Panel b: zoom-in onto the relevant area. Panel c: final eccentricity as a function of the final semi-major axis.