Effect of corotation on trapped particle trajectory. Particles with a charge-to-mass ratio 10⁻⁵ q_e /m_p are released from a circular orbit of radius 0.04 AU and inclination of 5°. The solid (dashed) lines show the distance from the Sun along the trajectories corresponding to the cases without (with) corotation. The radial velocity profile given by Eq. (14) is used. The particles are emitted at t = 0, but the difference in phase between the trajectories is visible only at later times.