Modeling of two CoRoT solar analogues constrained by seismic and spectroscopic analysis

TL;DR

This study uses seismic, spectroscopic, and evolutionary modeling to precisely characterize two solar analogues observed by CoRoT, providing improved estimates of their fundamental parameters and age, enhancing understanding of Sun-like stars.

Contribution

It presents a combined seismic and spectroscopic analysis with evolutionary modeling to accurately determine the properties of two solar analogues, incorporating chemical clocks for better age estimates.

Findings

HD42618 is slightly less massive and older than the Sun.

HD43587 is more massive and older than the Sun.

Models successfully reproduce seismic and spectroscopic data within uncertainties.

Abstract

Solar analogues are important stars to study for understanding the properties of the Sun. Evolutionary modeling, combined with seismic and spectroscopic analysis, becomes a powerful method to characterize stellar intrinsic parameters, such as mass, radius, metallicity and age.However, these characteristics, relevant for other aspects of astrophysics or exoplanetary system physics for example, are difficult to obtain with a high precision and/or accuracy. The goal of this study is to characterize the two solar analogues HD42618 and HD43587, observed by CoRoT. In particular, we aim to infer precise mass, radius, and age, using evolutionary modeling constrained by spectroscopic, photometric, and seismic analysis. These stars show evidences of being older than the Sun but with a relatively large lithium abundance. We present the seismic analysis of HD42618, and the modeling of the two solar analogs HD42618 andHD43587 using the CESTAM stellar evolution code. Models were computed to reproduce the spectroscopic (effective temperature and metallicity) and seismic (mode frequencies) data,and the luminosity of the stars, based on Gaia parallaxes. We infer very similar values of mass and radius for both stars compared to the literature, within the uncertainties, and reproduce correctly the seismic constraints. For HD42618, the modeling shows it is slightly less massive and older than the Sun. For HD43587, it confirms it is more massive and older than the Sun,in agreement with previous results. The use of chemical clocks improves the reliability of our age estimates.