Global 3-D solar-type star-disc dynamo systems: I. MHD modeling

We have carried out global three-dimensional magnetohydrodynamic simulations of the star-disc interaction region around a young solar-type star. T'he magnetic field is generated and maintained by dynamos in the star as well as in the disc. The developing mass flows possess non-periodic time-variable azimuthal structure and are controlled by the nonaxisymmetric magnetic fields. Since the stellar field drives a strong stellar wind, accretion is anti-correlated with the stellar field strength and disc matter is spiraling onto the star at low latitudes, both contrary to the generally assumed accretion picture. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.