We present results from an investigation of the dynamical behavior of buoyantmagnetic flux rings in the radiative interior of a uniformly rotatingearly-type star. Our physical model describes a thin, axisymmetric, toroidalflux tube that is released from the outer boundary of the convective core, andis acted upon by buoyant, centrifugal, Coriolis, magnetic tension, andaerodynamic drag forces. We find that rings emitted in the equatorial plane canattain a stationary equilibrium state that is stable with respect to smalldisplacements in radius, but is unstable when perturbed in the meridionaldirection. Rings emitted at other latitudes travel toward the surface alongtrajectories that largely parallel the rotation axis of the star. Over much ofthe ascent, the instantaneous rise speed is determined by the rate of heatingby the absorption of radiation that diffuses into the tube from the externalmedium. Since the time scale for this heating varies like the square of thetube cross-sectional radius, for the same field strength, thin rings rise morerapidly than do thick rings. For a reasonable range of assumed ring sizes andfield strengths, our results suggest that buoyancy is a viable mechanism forbringing magnetic flux from the core to the surface, being capable ofaccomplishing this transport in a time that is generally much less than thestellar main sequence lifetime.
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