Illustration of the flux variations induced by stellar activity on α Cen B and its correlation with the S-index on a small wavelength range in the extreme blue. Bottom: master normalised spectrum of α Cen B. Middle: river diagram of the five years of alpha Cen B observations. Some lines clearly show long trend flux variations corresponding to the magnetic cycle of the star. Top: Pearson correlation between the flux variations and the S-index showing, for several wavelengths, a significant correlation with |ℛ_Pearson| > 0.4 (red horizontal lines). Such correlations were already reported by previous studies for the 2010 dataset, such as Thompson et al. (2017), Wise et al. (2018), Ning et al. (2019), and Cretignier et al. (2020a). The 2010 observational season is equivalent to index 102–150 on the figure, for which the rotational modulation is clearly visible.