A non-extensive approach to the stellar rotational evolution - I. F- and
G-type stars
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 433 (3):
1789-1795 (2013)DOI: 10.1093/mnras/stt734
Abstract
The pioneering study by Skumanich showed that the rotational velocity of
G-type main-sequence (MS) stars decreases with stellar age according to
<< v sin i >> proportional to 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.