Free Access
Fig. 2
Example of the drawing style in the initial period of 1825−1830. This full-disk drawing of 1827 June 13 shows large spots which combine several umbrae and at least part of the penumbral area, as is revealed by the detailed drawings.
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.