HARPS RVs and VPSD between March 1 and 15, 2019. Top panel: HARPS RVs for which the sub-rotational components are analyzed. The original observations are shown as black dots with red error bars. The RVs recreated from the sum of all fitted VPSD components on an even time grid with the same cadence and end points as the observations are shown in gray. Bottom panel: velocity power spectral density of the observed RVs (in gray) and the modeled components (colored curves), consisting of photon noise (dotted red), oscillations (dashed purple), granulation (dash-dotted cyan) and supergranulation (dash-dotted blue). The sum of the models (solid black) is optimized with respect to the black circles, which correspond to the true VPSD averaged on logarithmically equidistant frequency steps.