Left: Time series of activity indicators from HARPS-N spectra. Right: GLS periodograms of activity indicators. The horizontal lines mark 1% (dotted line) and 0.1% (dashed–dotted line) false-alarm probability levels, while vertical lines mark the orbital periods of the three planets. The line at P = 762 days marks the possible orbital period of the fourth planet that was uncovered in our later RV analysis (see Section 4.2).