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

Solar analogues are important objects for understanding the properties of the Sun. Evolutionary modeling, combined with seismic and spectroscopic analysis, becomes a powerful methods to characterize stellar intrinsic parameters, such as mass, radius, metallicity and age. However, these characteristics, relevant for other aspects of astrophysics or exosystem 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 modeled the two solar analogs using two different evolution code: TGEC and CESTAM. Models were computed to reproduce the spectroscopic (effective temperature, metallicity, lithium abundance) and seismic (frequency separations) data, and the luminosity of the stars, computed using Gaia parallaxes. Despite two different approaches, we infer very similar values of mass and radius for both stars, within the uncertainties, and reproduce correctly the frequency separations. For HD42618, the two modeling find very similar ages, confirming it is slightly less massive and older than the Sun. For HD43587, the two modeling give compatible values in age with a difference of 0.9 Gyr, and confirm it is more massive and older than the Sun. For both stars, we reproduce the lithium abundances with TGEC models by adjusting the parameters of the tachocline.