Free Access
Fig. 4

Generalised Lomb-Scargle periodogram of the HARPS-N time series of activity indicators (bisector span,
log ,
ΔV, Vasy(mod) and Hα). Reference lines have the same colour code than in Fig. 3.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.