Position of target stars in the Gaia color-magnitude diagram. The absolute Gaia RP magnitudes are calculated using parallax-based distances from Table 3. Magnitudes are corrected for interstellar extinction (details provided in the text), but no corrections are made for the contribution of additional radiation sources within the symbiotic system (e.g., the symbiotic nebula, which may cause the stars to appear bluer and brighter). The evolutionary tracks correspond to the same initial masses as shown in Fig. 3.