Left: spatial distribution of sources considered in this study. Blue points show stars previously associated with the Mon R2 region from infrared and X-ray surveys, which are mainly concentrated in the central cluster and the two groupings to the east: GGD 12-15 and GGD 16-17. Red points result from our initial Gaia query and show the broad distribution of the optical sources that we tested for potential cluster membership. Right: histograms in proper motion R.A., proper motion decl., and parallax with red indicating the Gaia stars and blue bars showing the ±3σ range of the previously associated stars. The lower right panel is a color–magnitude diagram in Gaia G-RP vs. RP filters for the same two populations.