Poster
R. Costa, T. L. Campante, M. J. P. F. G. Monteiro, N. A. M. Moedas
Abstract
Asteroseismology has become an increasingly relevant way to determine the global
properties of stars and peer into their inner structure, both through advances on the
observational and theoretical side. Our work goes to its observational frontier by focusing on ε
Indi, the coldest star in which asteroseismic modes have been detected, and, on the theoretical
side, performs a detailed study of stellar and asteroseismic modelling. We focus on the surface
term, a systematic error in oscillation frequencies between models and observations, whose
cause will be closely linked to the unique properties of ε Indi, such as its large convective
envelope along with a high density and opacity. To do this we created over 2000 stellar tracks
until the end of the main-sequence using the stellar evolution code MESA, computing the
asteroseismic modes for each model with GYRE. We then performed model optimization using
AIMS, comparing our grid of models with the observations for ε Indi, utilizing the different
options for the surface term correction available in it. This work enables us to know how
asteroseismic properties such as the large and small frequency separation behave in K-type
stars and how they depend on our grid parameters. To conclude that the different surface term
corrections give compatible results in model optimization and about the impact that the different
choices in the model physics can have on the mode frequencies, such as the atmosphere or
convective efficiency.
8th TESS/15th Kepler Asteroseismic Science Consortium Workshop
Porto, Portugal
2024 July
