A non-extensive approach to the stellar rotational evolution – I: F- and G-type stars

• Autor(a) principal: Freitas, D. B. de
• Data de Publicação: 2013
• Outros Autores: Medeiros, José Renan de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/jspui/handle/123456789/29106
• topic: Evolution – stars; Rotation – stars; Statistics

The pioneering study by Skumanich showed that the rotational velocity of G-type mainsequence (MS) stars decreases with stellar age according to v sin i ∝ t −1/2. This relationship is consistent with simple theories of angular momentum loss from rotating stars, where an ionized wind is coupled to the star by a magnetic field. The present study introduces a new approach to the study of stellar rotational braking in unsaturated F- and G-type stars limited in age and mass, connecting angular momentum loss by magnetic stellar wind with Tsallis non-extensive statistical mechanics. As a result, we show that the rotation–age relationship can be well reproduced using a non-extensive approach from Tsallis non-extensive models. Here, the index q, which is related to the degree of non-extensivity, can be associated with the dynamo process and to magnetic field geometry, offering relevant information on the level of stellar magnetic braking for F- and G-type MS stars.