Stellar rotation: Evidence for a large horizontal turbulence and its effects on evolution

Astrophysics, abstract
astro-ph/0301258

From: Georges Meynet <georges.meynet@obs.unige.ch>

Date: Tue, 14 Jan 2003 16:02:32 GMT   (46kb)

Authors:
André Maeder

Comments: 8 pages, 5 figures, accepted for publication in A& A

We derive a new expression for the coefficient $D_{mathrm{h}}$ of diffusion
by horizontal turbulence in rotating stars. This new estimate can be up to two
orders of magnitude larger than given by a previous expression. As a
consequence the differential rotation on an equipotential is found to be very
small, which reinforces Zahn’s hypothesis of shellular rotation. The role of
the so–called $mu$–currents, as well as the driving of circulation, are
reduced by the large horizontal turbulence. Stellar evolutionary models for a
20 M${odot}$ star are calculated with the new coefficient. The new and large
$D_{mathrm{h}}$ tends to limit the size of the convective core and at the same
time it largely favours the diffusion of helium and nitrogen to the surface of
rotating OB stars, a feature supported by recent observations.

References and citations for this submission:

SLAC-SPIRES HEP (refers to ,
cited by, arXiv reformatted)