Oral comunication
N. A. M. Moedas, D. Bossini, M. Deal
Abstract
A star born with a specific composition will not keep it during its evolution. It changes
not only with the nuclear reactions, but also due to the chemical transport mechanisms that
modify the complete distribution over time. Atomic diffusion is one of the main transport
processes taken into account in stellar models, and it can be divided into two main processes,
gravitational settling and radiative accelerations. These two processes are in competition, but
are neglected in F-type and more massive stars because they produce chemical over-variations
at the stellar surface that are unrealistic. Moreover, the current method of calculating radiative
acceleration is very computationally expensive and does not allow it to be included in every
stellar model. In order to improve and include radiative accelerations in the stellar models, we
have implemented a new calculation method in MESA, the Single Value Parameter (SVP). SVP
is a more efficient way of calculating radiative accelerations and allows a large number of stellar
models to be calculated. Using these new stellar models, we built a stellar grid and used it to
characterise a Kepler sample. We show that systematics of up to 5%, 3% and 30% in the
inferred mass, radius and age of F-type stars are obtained when chemical transport
mechanisms are neglected. These models are a step toward a more accurate understanding
and characterisation of F-type stars.
8th TESS/15th Kepler Asteroseismic Science Consortium Workshop
Porto, Portugal
2024 July
