Quality summary of the primary sample (15 681 sources). Position and relative parallax error as a function of the parameter astrometric_excess_noise_sig or significance of excess noise (left panels). Lindegren et al. (2018) indicate that astrometrically well-behaved sources have a significance of excess noise ≤2 (region on the left of the red line). The green line in the left-hand, bottom panel signals σ_π/π = 0.2. Dependency between quality flags (right panels). Lindegren et al. (2018) state that sources with astrometric_gof_al or goodness of fit <3 (below the green line of the top panel), mean_varpi_factor_al or mean parallax factor AL in the interval [−0.23, 0.32] (between the green lines of the middle panel), and visibility_periods_used or visibility periods >8 (above the green line of the bottom panel) should be used. Not shown here, but also applied, is rv_nb_transits or number of observations used to compute the value of the radial velocity >5.