Model isochrones from Yi et al. (2001) for the metallicities of HAT-P-42 (left) and HAT-P-43 (right) and ages of 1 to 13 Gyr in 1 Gyr increments (left to right). The adopted values of effective temperature, T_eff ⋆, and a/R_⋆ are shown together with their 1σ and 2σ confidence ellipsoids. In each plot the initial values of T_eff ⋆ and a/R_⋆ from the first SPC (see Sect. 3) and light curve analyses are represented with a triangle.