Contenidos
Imágenes
Subir su imagen
DSS Images Other Images
Artículos relacionados
Magnetic structure in cool stars. XV - The evolution of rotation rates and chromospheric activity of giants
For cool giants and subgiants the observed dependence of rotationalvelocity and Ca II H and K line-core emission on color B-V isinterpreted in terms of changes in the moment of inertia by stellarevolution. Modeling of the rotational velocity during the evolution ofcool giants with masses between 2.0 and 3.0 solar masses, by taking intoaccount the change in the moment of inertia and assuming rigid-bodyrotation and conservation of angular momentum, describes the observeddecrease of v sin i with B-V. The computed evolution of the rotationalvelocity, together with the empirical relation between the Ca IIline-core emission and the rotation rate, explain the observed drop inthe Ca II line-core emission for giants at B-V = about 0.95. Forsubgiants with masses of about 1.5 solar mass, the change in the momentof inertia by itself cannot explain the observed v sin i distribution:there are indications of loss of angular momentum, presumably bymagnetic braking.
|
Enviar un nuevo artículo
Enlaces relacionados
- - No se han encontrado enlaces -
En viar un nuevo enlace
Miembro de los siguientes grupos:
|
Datos observacionales y astrométricos
| Constelación: | Ballena |
| Ascensión Recta: | 00h12m22.17s |
| Declinación: | -08°42'35.2" |
| Magnitud Aparente: | 8.895 |
| Distancia: | 497.512 parsecs |
| Movimiento Propio en Ascensión Recta: | 46.9 |
| Movimiento Propio en Declinación: | 0.1 |
| B-T magnitude: | 10.064 |
| V-T magnitude: | 8.992 |
Catálogos y designaciones:
|
