Panel a: Gaia HRD of the stars with ϖ > 10 mas with adapted photometric filters (see text, 240 703 stars) overlaid with all cross-matched GUCDS (Smart et al. 2017) stars with σ_ϖ∕ϖ < 10% in blue (M type), green (L type), and red (T type). Pink squares are added around stars with tangential velocity VT > 200 km s−1. Panel b: BT-Settl tracks (Baraffe et al. 2015) of solar metallicity for masses from 0.01 M⊙ to 0.08 M⊙ in steps of 0.01 (the upper tracks correspond to lower masses) plus in pink the same tracks for [M/H] = −1.0. Panels c and d: same diagrams using the 2MASS colours.