An Improved Metallicity Calibration with UBV Photometry

TL;DR

This paper presents a new calibration method for estimating stellar metallicities using UBV photometry, which improves accuracy by employing metallicity-dependent guillotine factors and homogenizing data from multiple sources.

Contribution

The study introduces a metallicity calibration based on metallicity-dependent guillotine factors and homogenizes data from various authors for enhanced accuracy.

Findings

New calibration formula with improved accuracy.

Metallicity-dependent guillotine factors outperform free guillotine factors.

Enhanced metallicity estimates aid Galactic component studies.

Abstract

We used the data of 701 stars covering the colour index interval 0.32<B-V<=1.16, with metallicities -1.76<=[Fe/H]<=+0.40 dex, which were taken from PASTEL catalogue and estimated metallicity dependent guillotine factors which provide a more accurate metallicity calibration. We reduced the metallicities of 11 authors to the metallicities of Valenti & Fischer (2005), thus obtained a homogeneous set of data which increased the accuracy of the calibration, i.e. [Fe/H]=-14.316*delta^{2}_{0.6}-3.557*delta_{0.6}+0.105. Comparison of the metallicity residuals, for two sets of data, based on the metallicity dependent guillotine factors with the ones obtained via metal free guillotine factors, shows that metallicities estimated by means of new guillotine factors are more accurate than the other ones. This advantage can be used in the metallicity gradient investigation of the Galactic components, i.e. thin disc, thick disc and halo.