Theoretical predictions for OsC modes comparing light and RV variations, normalised so that their maxima are unity. Upper panel: Light curves predicted for the superposition of sectoral prograde g modes with m = 1, 2, 3, using amplitude ratios of 1 : 0.37 : 0.14, consistent with the amplitudes in the Kepler Fourier diagram (Fig. 3). The black solid line represents a model where the initial phases of all modes are identical. To investigate the impact of phase shifts, the m = 3 mode is adjusted as shown, while the m = 2 mode’s initial phase is aligned with that of the m = 1 mode. The green curve illustrates a scenario where only the spike (m = 1) is observable, with no contributions m = 2 and m = 3 modes. Lower panel: RV variations predicted for the same prograde g modes, using the same amplitude ratios and phase offsets as in the upper panel. The green line corresponds to a model with only the m = 1 mode. See text for more details.