Magnetic star models with a consistent α#betta#-effect core-dynamo and radiative envelope

Models of middle main-sequence magnetic stars are constructed which have a convective core in which the field is generated by a dynamically consistent 'α#betta#-effect'dynamo. The envelope is at first assumed to be in strict radiative equilibrium with no meridional circulation. Later more general models are constructed, which include a thermally driven meridional circulation in the envelope consistent with the MHD equation. The magnetic field is restricted to have dipolar angular form, with its axis aligned with the rotation axis. These models are direct analogues of earlier models in which the field was implicitly assumed to be of fossil origin. Similar to the situation for the latter models, solutions could not be found for slow rotation and small internal flux. In general, the ratio of interior to surface fields in these 'core-dynamo' models is somewhat less than for the previous 'fossil' models. For the zero envelope circulation calculations this ratio increases as (lambdasub(Ω) lambdasub(H))sup(1/3) as lambdasub(Ω)/lambdasub(H) becomes large, compared with (lambdasub(Ω)/lambda sub(H))sup(1/2) from the previous investigations. (author)