Comparison of the location of the stars and a PARSEC (Bressan et al. 2012) isochrone of metallicity –2.5 and age 12 Gyr on a G₀ magnitude versus magnitude diagram. The isochrone on the plot has been computed for an age of 12 Gyr and a metallicity of − 2.5 dex. Here we show BP-RP (BP and RP are the respective magnitudes measured by the two low-resolution spectrographs, the Blue Photometer (BP) and the Red Photometer (RP) onboard the Gaia satellite) versus the absolute G magnitude. The red symbols represent our stars.