Time evolution of mass-weighted argument of the pericenter for a disc without particles (upper plot) and of mass-weighted eccentricity (lower plot) for 50 000 yr after applying a running window average. Time is given in terms of binary orbits, where each orbit corresponds to 66.7 yr. We find transition from circulation to oscillation within 200 binary orbits for ϖ_mw and a subsequent oscillation around ≈0.6 rad. A damped oscillation is visible for e_mw, reaching a value around ≈0.0275.