1 M_⊙ evolutionary tracks obtained with the α values calibrated with the Eddington T(τ) relation. The solid lines are tracks with varying α which follows Eq. (4). The dashed lines indicate those with α fixed to the solar values (Table 1). In case of CGM2, the calibrated α^* is negative for low T_eff and g as mentioned in Sect. 3.4.1. In this figure, we truncated the negative-α^* part of the evolutionary track with varying α^* for CGM2.