X-ray surface flux versus Gaia G_BP – G_RP color for the M 10PC-GAIA SAMPLE. Each star is represented by its mean X-ray emission level from our multi-mission data base. Colored areas mark the range of surface flux for four typical non-flaring magnetic regions in the solar corona, coronal holes (CH), background corona (BKC), active regions (AR), and cores of active regions (CO); see Table 3. The flux ranges of the BKC and CH overlap. Only two stars are located within or in the immediate vicinity of the “coronal hole” area: the binary pair GJ 745 A and B, where the upper limit is given for the A component of the system.