Variation of the standard deviation and correlation of the proper motion distributions for the field stars around HIP 82545 (µ² Sco) as a function of magnitude. Each point comes from a 2D Gaussian fit over a narrow magnitude bin (shown in Fig. 3). Each bin includes 200 stars in a 0.3° sky area around the target star. Crosses denote fits using stars with 2MASS magnitudes, and circles denote those with magnitudes computed from the Gaia colour transformation.