T_eff − R_* distributions for all clusters in this study. Each panel shows the distribution of high probability members of the open cluster indicated in the panel title. Stellar radii R_* are given in units of solar radii. Uncertainties on T_eff and R_* (gray error bars) were propagated from the photomety, the color-T_eff relations, and empirical T_eff − R_* relations. The uncertainties on R_* were typically ∼10−15%, which matches the scatter in the empirical T_eff − R_* relations. The uncertainties on T_eff roughly correspond to the size of the temperature bins that we chose in this work (see, for example, Fig. 4). Bottom right panel: all five cluster samples together for comparison.