Time evolution of star 2 on the V−I vs. B−V CCD, color coded by year, superposed on a grid of T_eff and A_V. From right to left, temperature increases with a step of 250 K and is shown as a dotted line. Temperatures of 5 kK and 6 kK are noted. From the bottom up, the solid lines indicate models with increasing extinction, with a step of 0.2 mag. A_V values of 0.0 and 1.0 mag are noted in the right side of the panel. We note the degeneracy of the parameters for T_eff> 6000 K.