Example of variability in the circumstellar Ca II K component of HD 85905 on timescales of days. The plot shows the weighted mean of spectra obtained close in time at the beginning of four consecutive nights starting around UT 23:00 on 3–6 March 2016, with 4, 4, 3, and 3 spectra contributing to the respective means. Variability in the component at ∼ 23 km/s is clearly visible; its minima, joined by a red line, are redshifted by ∼ 2 km/s from spectrum A to D, hinting to a mild acceleration of the clump of gas producing that absorption.