Das Strahlungsgleichgewicht rotierender und äußeren Kräften unterworfener Sterne

Vogt, Helle

doi:10.1002/asna.19262272003

Cited by 8 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Meridional circulation is generated in the radiative zone of a rotating star as a result of the thermal imbalance induced by the breaking of the spherical symmetry (Eddington 1925;Vogt 1926), structural adjustments and surface extraction of angular momentum (Decressin et al 2009). Transporting matter and angular momentum, this circulation creates differential rotation in the radiative zones, which makes the stellar interior highly turbulent.…”

Section: Shellular Rotationmentioning

confidence: 99%

Effects of rotational mixing on the asteroseismic properties of solar-type stars

Eggenberger

Meynet

Maeder

et al. 2010

A&A

View full text Add to dashboard Cite

Context. Observations of solar-like oscillations obtained either from the ground or from space stimulated the study of the effects of various physical processes on the modelling of solar-type stars. Aims. The influence of rotational mixing on the evolution and asteroseismic properties of solar-type stars is studied. Methods. Global and asteroseismic properties of models of solar-type stars computed with and without a comprehensive treatment of shellular rotation are compared. The effects of internal magnetic fields are also discussed in the framework of the Tayler-Spruit dynamo.Results. Rotational mixing changes the global properties of a solar-type star with a significant increase of the effective temperature resulting in a shift of the evolutionary track to the blue part of the HR diagram. These differences observed in the HR diagram are related to changes of the chemical composition, because rotational mixing counteracts the effects of atomic diffusion leading to larger helium surface abundances for rotating models than for non-rotating ones. Higher values of the large frequency separation are then found for rotating models than for non-rotating ones at the same evolutionary stage, because the increase of the effective temperature leads to a smaller radius and hence to an increase of the stellar mean density. In addition to changing the global properties of solartype stars, rotational mixing also has a considerable impact on the structure and chemical composition of the central stellar layers by bringing fresh hydrogen fuel to the central stellar core, thereby enhancing the main-sequence lifetime. The increase of the central hydrogen abundance together with the change of the chemical profiles in the central layers result in a significant increase of the values of the small frequency separations and of the ratio of the small to large separations for models including shellular rotation. This increase is clearly seen for models with the same age sharing the same initial parameters except for the inclusion of rotation as well as for models with the same global stellar parameters and in particular the same location in the HR diagram. By computing rotating models of solar-type stars including the effects of a dynamo that possibly occurs in the radiative zone, we find that the efficiency of rotational mixing is strongly reduced when the effects of magnetic fields are taken into account, in contrast to what happens in massive stars.

show abstract

Section: Shellular Rotationmentioning

confidence: 99%

Effects of rotational mixing on the asteroseismic properties of solar-type stars

Eggenberger

Meynet

Maeder

et al. 2010

A&A

View full text Add to dashboard Cite

show abstract

“…Meridional circulation takes place in the radiative interiors of rotating stars where it is generated by the thermal imbalance induced by the departure from spherical symmetry (Eddington 1925;Vogt 1926). Once established, this large scale circulation generates in turn advection of momentum and thus favours the development of strong horizontal diffusion through shear instability, which is the main source of turbulence 1 (Zahn 1992;Maeder & Zahn 1998).…”

Section: Rotation Induced Mixingmentioning

confidence: 99%

Rotational mixing in low-mass stars

Palacios¹,

Talon

Charbonnel³

et al. 2003

A&A

172

209

View full text Add to dashboard Cite

Abstract. We present a first set of results concerning stellar evolution of rotating low-mass stars. Our models include fully consistent transport of angular momentum and chemicals due to the combined action of rotation induced mixing (according to Maeder & Zahn 1998) and element segregation. The analysis of the effects of local variations of molecular weight due to the meridional circulation on the transport of angular momentum and chemicals are under the scope of this study. We apply this mechanism to low mass main sequence and subgiant stars of population I. We show that the so-called µ-currents are of major importance in setting the shape of the rotation profile, specially near the core. Furthermore, as shown by Talon & Charbonnel (1998) and Charbonnel & Talon (1999) using models without µ-currents, we confirm that rotation-induced mixing in stars braked via magnetic torquing can explain the blue side of the Li dip, as well as the low Li abundances observed in subgiants even when µ-currents are taken into account. We emphasize that µ variations are not to be neglected when treating rotation-induced mixing, and that they could be of great importance for latter evolutionary stages.

show abstract

“…In the radiative interiors of rotating stars, meridional circulation is generated as a result of the thermal imbalance induced by the breaking of the spherical symmetry (Eddington 1925;Vogt 1926). This large scale circulation transports matter and angular momentum.…”

Section: Shellular Rotationmentioning

confidence: 99%

The Geneva stellar evolution code

Eggenberger

Meynet

Maeder

et al. 2007

Astrophys Space Sci

300

230

View full text Add to dashboard Cite

This paper presents the Geneva stellar evolution code with special emphasis on the modeling of solar-type stars. The basic input physics used in the Geneva code as well as the modeling of atomic diffusion is first discussed. The physical description of rotation is then presented. Finally, the modeling of magnetic instabilities and transport of angular momentum by internal gravity waves is briefly summarized.

show abstract

Das Strahlungsgleichgewicht rotierender und äußeren Kräften unterworfener Sterne

Cited by 8 publications

References 0 publications

Effects of rotational mixing on the asteroseismic properties of solar-type stars

Effects of rotational mixing on the asteroseismic properties of solar-type stars

Rotational mixing in low-mass stars

The Geneva stellar evolution code

Contact Info

Product

Resources

About