Free Access
Fig. 15

Number and frequency of stars with and without circumstellar envelopes per spectral subtype in open clusters with different ages: a) between 3 Myr and 10 Myr, b) between 10 Myr and 40 Myr, and c) older than 40 Myr. The plots show a cleartrend of the appearance of the Be phenomenon with age.
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.