Metallicity calibration for solar type stars based on red spectra

Based on a high resolution and high signal-to-noise ratio (S/N) spectral analysis of 90 solar-type stars, we have established several new metallicity calibrations in the T_eff range [5600, 6500] K based on red spectra with the wavelength range of 560–880 nm. The new metallicity calibrations are applied to determine the metallicity of solar analogs selected from Sloan Digital Sky Survey (SDSS) spectra. There is a good consistent result with the adopted value presented in SDSS-DR7 and a small scatter of 0.26 dex for stars with S/N > 50 being obtained. This study provides a new reliable way to derive the metallicity for solar-like stars with low resolution spectra. In particular, our calibrations are useful for finding metal-rich stars, which are missing in the SEGUE Stellar Parameter Pipeline.