Ratios of the equivalent widths (EWs) to the 9632 and 9577 Å absorptions, before (left) and after (right) removal of the stellar Mg II line that contaminates the latter. EWs are from Table 2 of Galazutdinov et al. (2017) and the ratio is displayed as a function of the target star surface gravity represented by the log(g) parameter. Parameters a (intercept) and b (gradient) of a linear fit are listed in the graph as well as the Pearson (Pr) and r-squared (r₂) correlation coefficients. The horizontal line indicates the EW ratio derived from the laboratory data.