Color maps indicating the pairwise (marginalized) correlation between the parameters in the (fine) grid of MESA models. Top left: correlation between X_c and f_ov after marginalizing over M_⋆. Top right: correlation between M_⋆ and X_c after marginalizing over f_ov. Bottom left: correlation between M_⋆ and f_ov after marginalizing over X_c, indicating the strong correlation caused by models with the ΔΠ same value. The same color scale was used for all panels. The 20 best MESA models are indicated by the black crosses.