Best-fitting MESA tracks with Z = 0.0148 (left-side) and Z = 0.0188 (right-side) and calculations with mixing-length parameter fixed to the solar-calibrated value and element diffusion neglected. For Z = 0.0148, the dotted tracks show the effect of increasing the masses of the components by 3σ. Position of both components are indicated with errorbars. Small crosses denote position of the best fit in the three-dimensional space of parameters {T_eff, L, R}.