Poster
R. Costa, T. L. Campante, M. J. P. F. G. Monteiro, M. Deal
Abstract
In K-type stars, with masses from 0.6 to 0.9 solar masses and effective temperature from 3900 K to 5300 K, a systematic discrepancy exists between the values for the modelled and interferometric radii. Stellar models tend to underestimate the radius by about 3-5%, while also overestimating the effective temperature by approximately 5%. In our work, we will analyse this discrepancy for K-type stars with stellar oscillations, whose measurement has only been recently possible through advanced spectrographs such as ESPRESSO and Keck Planet Finder. Our sample will include the stars œμ Indi, œÉ Draconis, HD 219134, HD 131977 and HD 191408. To determine the properties of our sample of stars, we will use a large grid of stellar models calculated using MESA, with asteroseismic modes computed by GYRE. We then perform model optimization using AIMS, comparing our grid of models to the asteroseismic and interferometric observational constraints of each star. One suggested solution for mitigating this discrepancy is through the calibration of the mixing length parameter, which controls the efficiency of energy transport by convection, and that has a direct impact on the radius. That is why in our forward modelling procedure the mixing length is a free parameter, allowing us to obtain mixing length values different from the Sun, estimating the impact it has on the discrepancy between the modelled and interferometric radius.
XXXV Encontro Nacional de Astronomia e Astrofísica
Lisbon, Portugal
2025 September
