Calibration of Stellar Isochrones for G- and K-type Dwarfs based on High-Resolution Spectra

We present a recent progress on calibration of stellar isochrones based on a set of high-resolution spectra for 170 G- and K-type dwarfs in the solar neighborhood. We compare observed magnitudes of these stars in a number of broad passbands [UB(B_T)V(V_T)RIJHK] with model magnitudes generated using ATLAS9 synthetic library at the previously derived set of spectroscopic parameters. We find systematic offsets in colors from these passbands, which are mainly revealed as a function of effective temperature of stars. In order to remove these systematic color mismatches, we derive correction functions and apply them to the model spectra.