Figure 4: Relation between residual flux in the core of the infrared Ca II 8542 line and the S index for 11 stars that have been observed with both the Subaru and LAMOST telescope.
From: Observational evidence for enhanced magnetic activity of superflare stars
A clear correlation is seen between the two activity indicators. The clear correlation between the measured activities indicates that the S index we obtain with LAMOST observations is a reliable measure of chromospheric emission. The error bars are calculated using the relation in Supplementary Fig. 2. The error bars in the figure represent a single standard deviation.
