Fig. 2

Schematic picture of how the GBS are differentiated against each other. Stars are associated in five different groups according to their spectral type. One star is chosen as a reference for each group (in red). The rest of the stars in that group is analysed with respect to the reference star, and are connected with arrows. The reference stars are finally analysed with respect to the Sun, which is the zero point.
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.