Evaluation of the Gaia astrometric solution. The limits of PM error (0.5 mas yr⁻¹) and parallax error (0.5 mas) are shown as horizontal dashed lines. First two panels: errors vs. Gaia PMs in RA (left) and Dec (middle), respectively. A Gaussian profile is fitted to PM in each dimension and the limits of ±5σ are calculated (vertical dashed lines). The selected targets are shown in blue color. Last panel (right): errors vs. Gaia parallaxes. A Gaussian fitting is adopted again for the parallax, while an additional elliptical constraint has also been applied with the 5σ limits of PM_RA and PM_Dec taken as the primary and secondary radii, respectively. The same criteria of ±5σ were calculated for the parallax (vertical dashed lines). The final selected targets are shown in red color. Green contours show the number density in each diagram.