Empirical Bolometric Correction Coefficients for Nearby Main-Sequence Stars in Gaia Era

TL;DR

This study derives empirical bolometric correction coefficients and intrinsic colour-temperature relations for nearby main-sequence stars using Gaia data, improving stellar parameter calibrations across a wide temperature range.

Contribution

It provides new empirical $BC-T_{eff}$ and colour-$T_{eff}$ relations based on high-quality Gaia data for main-sequence stars, extending calibration accuracy.

Findings

Calibrated $BC-T_{eff}$ relation valid from 3100 to 36000 K.

Derived two intrinsic colour-$T_{eff}$ relations for different temperature regimes.

Tabulated new $BC$ values for use in stellar parameter estimation.

Abstract

Nearby detached double-lined eclipsing binaries with most accurate data were studied and 290 systems were found with at least one main-sequence component having a metallicity $0.008\leq Z\leq 0.040$. Stellar parameters, light ratios, Gaia DR2 trigonometric parallaxes, extinctions and/or reddening were investigated and only 206 systems were selected eligible to calculate empirical bolometric corrections. NASA-IPAC Galactic dust maps were main source of extinctions. Unreliable extinctions at low Galactic latitudes $|b|\leq5^o$ were replaced with individual determinations, if they exist in the literature, else associated systems are discarded. Main-sequence stars of remaining systems were used to calculate bolometric corrections ($BC$) and to calibrate $BC-T_{eff}$ relation, which is valid in the range 3100-36000 K. De-reddened $(B-V)_0$ colours, on the other hand, allowed us to calibrate two intrinsic colour effective temperature relations, where the linear one is valid for $T_{eff}>10000$ K, while the quadratic relation is valid for $T_{eff}<10000$ K, that is, both are valid in the same temperature range $BC-T_{eff}$ relation is valid. New $BC$ computed from $T_{eff}$ and other astrophysical parameters are tabulated, as well.