Same as Fig. 4 for stars with metallicities lower than −1.2 dex. Yonsei-Yale evolutionary tracks for [Fe/H] = −1.29 (black, to the right) and −2.29 (blue, to the left), and [α/Fe] = +0.3, for masses between 0.5 and 1.0 M_⊙, in steps of 0.1 M_⊙. Clearly, ψ Phe ([Fe/H] = −1.2), Gmb 1830 (−1.5) and HD 122563 (−2.6) lie outside the range of the tracks with corresponding metallicities. HD 84937 and HD 140283 have metallicities close to the −2.29 tracks, resulting in derived masses of about 0.75 and 0.7 M_⊙, respectively.