Evolution of the rotation pole for (291) Alice projected onto the reference frame ℰ′′ associated with the s₆ frequency term in the Fourier representation of the ζ = sin(I/ 2)exp(ıΩ) orbital parameter (see Sect. 2.2). Four panels are shown for four values of the dynamical flattening parameter Δ. The dashed lines show a grid of meridian and latitude circles in ℰ′′ with the north pole toward the center and the zero longitude meridian, ϕ = 0°, pointing to the bottom of each figure (the viewing angle is similar to that of the bottom and left panel in Fig. 1). The solid lines are isolines of constant Colombo Hamiltonian ℋ′(X′,ϕ) = C for frequency s = s₆ = −26.34′′/yr and inclination I = I₆ = 1.1°. In the middle panels the spin remains well confined in the resonant zone about the Cassini state C₂, in the extreme left and right panels the libration amplitude is larger and the perturbation due to the proper term in ζ brings the spin toward the limits of the Cassini resonance, indicating a possible long-term instability of the capture.