Absolute magnitude M_G against G − J colour (top), and bolometric luminosity against effective temperature from VOSA (bottom). Top panel: empty grey circles represent stars with poor photometric quality data in G, J, or both passbands (Sect. 2.2), poor astrometric quality data (RUWE > 1.41) or non-parallactic distances (Sect. 2.3), and close binary stars (Sect. 2.4). Bottom panel: empty grey circles represent stars with poor astrometric quality data or non-parallactic distances, and close binary stars. In both panels, black empty circles are the 36 known young overluminous stars identified in our sample. The remaining “regular” stars are colour-coded by spectral type.