Top panel: spectral window of spectroscopic time-series. The high-resolution view of the fine structure of the peaks is shown in the insert. Middle panel: least-squares power spectrum of LPVs of the original data. The ordinatae show the percentual data variance reduction. Lower panel: least-squares power spectrum with the 19 detected frequencies given as known constituents. The ordinates show the percentual reduction of the residual data variance after the fit with the known frequencies.