Trajectory of particles projected onto Phaethon’s equatorial plane at the perihelion, initially at H = 1 cm and rotating with Phaethon’s rotational speed. Hollow circles, separated by 5° in longitude, show the initial position of the particles of the same-colored trajectory lines: r_a = 1 μm (solid) and 2 μm (dotted). Letters show the flag (see text) of 1 and 2 μm particles for the first and second line, respectively. The rotation is anti-clockwise as indicated by the arrow, and the Sun is at x = − ∞ as shown by the hallow arrows, but below the xy-plane since the aspect angle is 101° > 90°, so a_total has non-zeroz component in this figure. This is why the orange solid line (r_a = 1 μm at longitude 80°) seems to penetrate into the asteroid, as the trajectory is projected onto the xy-plane. (a, c) olivine; (b, d) magnetite particles. (a, b) Morning terminator; (c, d) evening terminator.