Likelihood periodogram searches of the strongest periodic signal in the time series of the three activity indices provided (BIS SPAN, FWHM and )). Both the rotation period (most prominent in FWHM and ) index) and its first harmonic (most prominent feature in BIS SPAN) are clearly seen in the activity time-series. In the three periodograms, the tested model contains sinusoid (ciruclar orbit), an offset, a linear trend and a extra white-noise jitter component.