Snapshots of the planetesimal disk when the planet’s eccentricity increases with time. The left and right columns show the cases with τ_ecc = 10³ P_orb,p and 10³ P_orb,p, respectively. The upper and lower panels show the snapshots when the planetary eccentricity is e_p = 0.3 and 0.81, respectively. The vertical dotted lines are the pericenter and apocenter of the planet. The dashed lines are the analytical models of the planetesimal eccentricity given by Eq. (40). When τ_ecc = 10⁵ P_orb,p, the planetesimal eccentricity is smaller than that given by Eq. (40) because the resonances suppress the linear increase of the eccentricity.