Time series of the FWHM, BIS and V_asy CCF line diagnostics, and the log() and H_α activity indexes, shown next to their corresponding GLS periodograms (after removing the trends in the FWHM, log() and H_α data as described in the text). The dashed horizontal lines mark the mean values, to highlight the increasing trend visible in the FWHM, log(), and H_α data. Vertical dotted lines in the periodograms mark the locations of the stellar rotation period, as derived from K2 photometry, and its first harmonic. Bottom right panel: window function of the data. A zoomed view of the low-frequency part of the spectrum is shown in the inset panel, and a vertical dotted line marks the 1-y orbital frequency of the Earth.