Free Access

Fig. 5


Simulated values of the S-index as they would be measured for inclinations of 90° (red curves), 57° (magenta curves), 0° (blue curves) vs. facular surface coverage for solar, polar, and homogeneous distributions of active regions. The maximum possible facular surface coverage (i.e., when faculae and spots fully cover the activity belts/caps or the entire stellar surface) is about 28%, 19%, and 47% for the adopted solar, polar, and homogeneous distributions.

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.