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

M. Castro (1) , F. Baudin (2) , O. Benomar (3, 4) , R. Samadi (5) , T. Morel (6) , C. Barban (5) , J. D. Do Nascimento (7, 8, 2) , Y. Lebreton (5, 9) , P. Boumier (2) , J. P. Marques (2) , J. S. da Costa (1)

1 UFRN - Univesidade Federal do Rio Grande do Norte = Federal University of Rio Grande do Norte
2 IAS - Institut d'astrophysique spatiale
3 New York University [Abu Dhabi]
4 NAOJ - National Astronomical Observatory of Japan
5 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
6 Université de Liège
7 UFRN - Universidade Federal do Rio Grande do Norte [Natal]
8 CfA - Harvard-Smithsonian Center for Astrophysics
9 IPR - Institut de Physique de Rennes

Solar analogues are important stars to study for understanding the properties of the Sun. Combined with seismic and spectroscopic analysis, evolutionary modelling 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 high precision and/or accuracy. The goal of this study is to characterize the two solar analogues, HD 42618 and HD 43587, observed by CoRoT. In particular, we aim to infer their precise mass, radius and age, using evolutionary modelling constrained by spectroscopic, photometric and seismic analysis. These stars show evidence of being older than the Sun but with a relatively large lithium abundance. We present the seismic analysis of HD 42618, and the modelling of the two solar analogues, HD 42618 and HD 43587 using the cestam stellar evolution code. Models were computed to reproduce the spectroscopic (effective temperature and metallicity) and seismic (mode frequency) data, and the luminosity of the stars, based on Gaia parallaxes. We infer very similar values of mass and radius for both stars compared with the literature, within the uncertainties, and we reproduce correctly the seismic constraints. The modelling shows that HD 42618 is slightly less massive and older than the Sun, and that HD 43587 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.

Mots clés: asteroseismology; stars: abundances; stars: fundamental parameters; stars: interiors; stars: solar-type

Domaines: Physique [physics]

M. Castro, F. Baudin, O. Benomar, R. Samadi, T. Morel, et al.. Modeling of two CoRoT solar analogues constrained by seismic and spectroscopic analysis. Monthly Notices of the Royal Astronomical Society, 2021, 505 (2), pp.2151-2158. ⟨10.1093/mnras/stab1410⟩. ⟨hal-03330318⟩