Radial torque density Γ(r) acting on the embryo during the onset (top) and saturation (bottom) phases, normalised to Γ₀. The individual curves represent measurements in the periastron (purple), apoastron (orange) and in-between. The vertical arrows indicate the instantaneous radial distance of the embryo corresponding to the individual curves. The horizontal arrows and labels approximately distinguish some of the important torque contributions discussed in the text. To avoid misinterpretation, we remark that the hot-trail torque is acting in the bottom panel as well but it spans different radial extent for each curve and thus cannot be marked unambiguously.