Color-magnitude diagram for NGC 6819. We depict the combined binary tracks as solid, dotted, short-dashed, long-dashed, and three short-dashed colored lines. The dotted black line depicts the ZAMS, and the dot-dashed red line denotes the isochrone for NGC 6819 (in Log(t[yr])) for single models. The filled blue circles indicate BSSs, and the filled red circles indicate the age on tracks. The three numbers in the box denote the M₁/M₂/P donor mass (in M_⊙), the accretor mass (in M_⊙), and the period (in days).