Precise determination of fundamental parameters of six exoplanet host stars and their planets

Abstract

The aim of this paper is to determinate the fundamental parameters of six exoplanet host (EH) stars and their planets. Because techniques for detecting exo-planets yield properties of the planet only as a function of the properties of the host star, we must accurately determine the parameters of the EH stars first. For this reason, we constructed a grid of stellar models including diffusion and rotation-induced extra-mixing with given ranges of input parameters (i.e. mass, metallicity and initial rotation rate). In addition to the commonly used observational constraints such as the effective temperature Teff, luminosity L and metallicity [Fe/H], we added two observational constraints, the lithium abundance log N (Li) and the rotational period Prot. These two additional observed parameters can set further constraints on the model due to their correlations with mass, age and other stellar properties. Hence, our estimations of the fundamental parameters for these EH stars and their planets have a higher precision than previous works. Therefore, the combination of rotational period and lithium helps us to obtain more accurate parameters for stars, leading to an improvement in knowledge about the physical state of EH stars and their planets.