A evolução da rotação estelar na vizinhança solar
AUTOR(ES)
Daniel Brito de Freitas
DATA DE PUBLICAÇÃO
2006
RESUMO
Different studies point for an rotationage link following a α tα relationship. The value of the α -parameter has a strong role on the evolutionary behaviour of rotation, because it indicates how strong is the spindown once stars evolve. The well known Skumanichs relation α t −1/2, which is consistent with simple theories of angular momentum loss from rotating stars with magnetic fields and winds, is one of the best accepted. Nevertheless, several studies show clearly that such a relation cannot hold for stars much younger or much older than the Pleiades (100 Mega years) without leading to velocities much greater or much lower than those presently observed. The present study aims at improving this picture on the basis of an enlarged analyses taking into account the role of mass and metallicity on the rotationage relation, based on an unprecedented sample of about 14 000 stars in the solar neighbourhood. From this new approach we show that the αparameter it depends strongly on the stellar age and, by consequence, on the metallicity. In addition, one observes a strong dependence of the referred parameter on the single or binary status of the stars
ASSUNTO(S)
rotação do sol fisica relação rotação-idade - física rotação do sol lei de skumanich lei de skumanich
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