GLS periodograms of different activity indicators as inferred from the HARPS-N RV time series with the FAP levels at 1% and 0.1% marked as dashed and dotted red lines, respectively. First row: from left to right FWHM, FWHM_SN, A, and A_SN. Second row: from left to right BIS, γ, log R′_HK, and H_α, where the latter two were subject to a pre-whitening. The most prominent peak is always at ∼20 days, which is likely the stellar rotation period (P_rot,*).