Spectroscopic time series obtained with HARPS-N (green squares), HIRES (red circles), and APF (blue triangles) and used in this work. From the top to bottom panels: The RV, the log R′_HK, the Hα, and the BIS time series. Dashed orange lines represent the fifth-degree polynomial models used for the modeling of the long trend in the spectroscopic series. The RVs have been reported in the same scale by applying an offset to them; the log R′_HK series are calibrated in the same Mt. Wilson scale (Baliunas et al. 1995).