Periodograms of the HARPS RV data (blue), the spectral line bisector span (orange), and the cross-correlation function full-width at half maximum (FWHM, green). The FWHM and bisector span were only available for the HARPS data, and so the AAT and Keck data are not included in the power spectra shown here. The full vertical line shows the period of λ² For b, and the dashed line is the secondary 33-day periodicity. The comb of peaks around the orbital period of λ² For b are caused by the observational window function, as is the case for many of the peaks around the 33-day periodicity.