Gaia charts for the stars in samples 1, 2, and 3 (left) and stars in differential sample 3–4 (right). The same three circles as in Fig. 1 are plotted. Symbol size represents G₃′ magnitude, symbol color G_BP, 3 − G_RP, 3, and arrows proper motion. The magnitude and color scales are common to both panels (see legend) and stars without a valid G_BP, 3 − G_RP, 3 are shown without a color. The proper motions have the mean value derived for sample 1 subtracted and the two scales are different, as indicated in the legend. Only the proper motions for the 100 brightest stars in each panel are shown.