CMD of UMi’s member stars from Sestito et al. (2023), Pace et al. (2020) and Kirby et al. (2010) (blue, orange, and red symbols, respectively), overlaid by Padua stellar isochrones (Bressan et al. 2012) for different combinations of age and metallicity. Left panels: stellar isochrones with metal abundance: Z = 0.0001, Z = 0.0002, and Z = 0.0003, and age t = 13 Gyr. Right panels: stellar isochrones with metal abundance: Z = 0.0001, Z = 0.0002, and Z = 0.0003, and age t = 1 Gyr. The filled symbols in different colours distinguish the various RR Lyrae subsamples: gold (black); known (cyan); new members (navy); and known, but not classified by Gaia DR3 as RR Lyrae stars (green). The magenta and yellow filled circles are known and new ACs belonging to UMi located within and beyond 12 r_h.