Fig. 1
Relation between V magnitude of the stars and the standard deviation σHα of the Hα index. Open symbols indicate quiet stars (see Sect. 4.3 for details), green diamonds are the bright stars sample. The continuous line represents the σjitter we adopted, while the orange asterisks indicate the mean photon noise value for each star.
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.