Generalized Lomb-Scargle periodograms of the 291 HARPS-N radial velocities and residuals as a function of frequency in cycles/day (or day⁻¹). From top to bottom are displayed the periodograms of radial velocities; residuals after subtracting the signal of Kepler-10 b; residuals after subtracting the signals of both Kepler-10 b and c; residuals after subtracting the signals of Kepler-10 b, c, and d; and the spectral window. The dotted vertical lines indicate the orbital periods of planets b (green), c (red), and d (light blue). The horizontal dash-dotted lines show the false alarm probability level of 10⁻⁵.