New photometric metallicity and absolute magnitude calibrations for F-G spectral type main sequence

In this thesis, metallicity and absolute magnitude calibrations in UBV photometry were found by using 893 F and G spectral type main-sequence stars, which have accurate spectroscopic, photometric and astrometric data selected from Solar neighbourhood. The new calibrations were applied to the main-sequence stars in the SA 141 star field and the metallicities and absolute magnitudes of the stars were estimated. In the star field of SA 141, it is found that the metallicity gradients must be calculated according to the absolute magnitude intervals of the stars. The metallicity gradients in the perpendicular directions to the Galactic plane were calculated as approximately -0.15 dex/kpc for all absolute magnitude intervals considered. Comparisons with the similar calibrations show that the best calibrations representing the original data are produced in this thesis. In addition, the distance comparisons between the Gaia stars and the calculated ones by the new absolute magnitude calibration in SA 141 star field revealed the effects of evolved and binary stars.