Top: Narval LSD I profiles. The mean profile is shown with a dashed red line. Bottom: dynamical plot of the residuals of the LSD I profiles compared to the mean LSD I profile, folded in phase with the ephemeris of BP07 (left) and with the same HJD₀ but the main pulsation period P_puls = 0.15175 d (right). The profiles have been rebinned in bins of 0.01 for the period of BP07 and 0.06 for the pulsation period.