Detalhes bibliográficos
| Ano de defesa: |
2006 |
| Autor(a) principal: |
Freitas, Daniel Brito de |
| Orientador(a): |
Medeiros, José Renan de |
| Banca de defesa: |
Não Informado pela instituição |
| Tipo de documento: |
Dissertação
|
| Tipo de acesso: |
Acesso aberto |
| Idioma: |
por |
| Instituição de defesa: |
Universidade Federal do Rio Grande do Norte
|
| Programa de Pós-Graduação: |
Programa de Pós-Graduação em Física
|
| Departamento: |
Física da Matéria Condensada; Astrofísica e Cosmologia; Física da Ionosfera
|
| País: |
BR
|
| Palavras-chave em Português: |
|
| Área do conhecimento CNPq: |
|
| Link de acesso: |
https://repositorio.ufrn.br/jspui/handle/123456789/16571
|
Resumo: |
Different studies point for an rotation age link following a <vrot> 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 Skumanich s relation <vrot> 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 rotation age relation, based on an unprecedented sample of about 14 000 stars in the solar neighbourhood. From this new approach we show that the α parameter 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 |
