Representation of the two possible orientations of the WASP-189 planetary system. The star is in its most probable state with the grey dashed curves marking constant stellar latitudes and with the north pole upward. In this representation, the stellar rotation causes the left and right hemispheres to appear blueshifted and redshifted, respectively. The stellar oblateness is highlighted by the grey dotted circle. The colour scale represents the stellar flux as seen by CHEOPS, including the limb darkening, the gravity darkening and the instrument passband. The black disc shows the planet to scale, and the black shaded area is made of several orbits drawn from the posterior probability distribution and highlights the uncertainty we obtain on the orbital orientation of WASP-189 b. The black arrows indicate the direction in which the planet crosses the stellar disc. The values of the stellar inclination i_⋆, the orbital inclination i_p and the projected orbital obliquity λ_p are displayed.