Gaia colour-magnitude Hertzsprung-Russell diagram for the 52 stars that we estimate have a close encounter with β Pic (see Table C.1). The grey field sources were obtained from a Gaia query using magnitude-over-error thresholds matching the lowest-quality values among the encounter sources: parallax>10 mas (maximum distance of 100 pc), parallax_over_error>58, phot_g_mean_flux_over_ error>220, phot_bp_mean_flux_over_error>2.3, and phot_rp_mean_flux_over_error>23.5. Symbols are colour-coded by spectral type.