Desynchronising mechanism of eccentricity tides. Tidal bulge raised on a planet by the host star in the heliocentric reference frame (left) and in a planetocentric reference frame rotating with the planet mean motion (right). The tidal gravitational forcing is assumed to be dominated by its eccentricity components, given by Eqs. (9) and (10). Because of the angular lag generated by dissipative processes, the rotation of the planet is accelerated by the component of degree s = 3 (the eastward propagating potential) in the vicinity of the periastron. Conversely, it is decelerated by the component of degree s = 1 (the westward propagating potential) to a lesser extent in the vicinity of the apoapsis.