Representation of the light curves for linear polarized (ψ = 0) dipole modes with different inclinations of the pulsation axis. This illustrates the cases discussed in Sect. A.0.1. In both figures, the position of the observer is fixed, i = 40°. Left panel: the dipole axis remains close to the line-of-sight during the rotation of the star. The observer only sees one hemisphere of the mode, and thereby does not observe a phase jump during the rotation period. Hence, a maximum and minimum of the rotational envelope of the pulsation are observed at Φ = 0 and Φ = π. Right panel: the dipole axis is now sufficiently inclined with respect to the line-of-sight so that the two hemispheres of the dipole can been seen by the observer. A phase jump by π radians occurs when the node of the oscillations crosses the plane (i,Ω). In this case, the amplitude of the rotational envelope leads to two maxima of different amplitudes (α(0) < α(π)).