Banca de QUALIFICAÇÃO: BERNARDO FORTON ODLAVSON GONÇALVES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : BERNARDO FORTON ODLAVSON GONÇALVES
DATE: 21/10/2022
TIME: 09:00
LOCAL: Auditório
TITLE:

Investigating the rotation of solar twins and analogs with the Toulouse-Geneva Stellar Evolution Code (TGEC)

KEY WORDS:

.stars: evolution - stars: interiors - stars: magnetic field - stars: rotation - stars: solar-type

PAGES: 58
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

One of the issues most debated nowadays in the field of stellar physics is the rotational evolution of the Sun and
Sun-like stars, especially regarding solar twins and analogs. There are numerous questions not yet answered in that area.
Among them is the comprehension of the phenomena that influence the amount of angular momentum that stars can have
during the Pre-Main Sequence phase and the understanding of the mechanisms that act in stellar interiors throughout evolution,
determining the rotation profiles observed. In all cases, we know that stellar magnetism plays a prominent role. In this work,
we use models computed with the Toulouse-Geneva Stellar Evolution Code (TGEC) to study the rotational evolution of three
samples of solar twins and analogs from the field, in addition to revisiting studies with analog stars from open clusters. We
used in our analysis two distinct magnetic braking prescriptions that simulate the loss of angular momentum due to stellar
winds. We found some discrepancies between our models and the studied stellar samples. For stars younger than the Sun, the
adjustment must be made by computing models with higher initial angular velocity. For stars older than the Sun, much is
currently discussed about the methods of calculating stellar ages, about the sample selection, and about a possible weakening
of the magnetic braking due to changes in the stellar dynamo. In addition to the improvements of the analysis carried out here,
we propose the implementation of the Tayler-Spruit dynamo equations to further investigate the role of magnetism on the
rotation of solar twins and analogs.

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