Fig. 3
CMD for the clean sample (points). Photometry from Gratton & Ortolani (1987) is also shown (crosses). Two isochrones (12−13 Gyr, Z = 0.003) from the PARSEC evolutionary tracks (Bressan et al. 2012) are shown. The blue straggler V1, an SX Phoenicis variable star (Mochejska et al. 2000) and a probable cluster member, is shown as a large empty circle.
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