Top: x (indigo) and y (beige) positions of the PSF centroid on the detector. For the orbit that falls between the dotted lines, the PSF occupies a position roughly ten pixels away compared to the other orbits. Bottom: similar to the top panel of Fig. 2, but displaying the first CHEOPS occultation observation. The orange lines display models including y and y² detector position in the baseline model. The violet lines display models instead including time in the baseline model.