GAPS programme at TNG. XXXIV.

We use these data to revisit the activity-rotation-age relationship. The time-series of the main optical activity indicators, namely CaII H & K, Balmer lines, NaI D_1_, D_2_, and HeI D_3_, % and use the were analysed together with the available photometry by using state-of-the-art Gaussian processes to model the stellar activity of these stars. Autocorrelation functions of the available photometry were also analysed.

We use the derived lifetimes for active region evolution to search for correlations with the stellar age, the spectral type, and the level of activity. We also use the pooled variance technique to characterise the activity behaviour of our targets. Our analysis confirms the decline of activity and rotation as the star ages.

We also confirm that the rotation rate decays with age more slowly for cooler stars and that, for a given age, cooler stars show higher levels of activity. We show that F- and G-type young stars early-type (F,G) young stars also depart from the inactive stars in the flux-flux relationship. The gaussian process analysis of the different activity indicators does not seem to provide any useful information on active region's lifetime and evolution.

On the other hand, active region's lifetimes derived from the light-curve analysis might correlate with the stellar age and temperature. Although we caution the small number statistics, our results suggest that active regions seem to live longer on younger, cooler, and more active stars.