Objective Magnetic fields play a key role in early phases of stellar evolution. I shall use the advanced technique of Zeeman-Doppler Imaging to map the spatial distribution of magnetic fields on the surfaces of young pre-main sequence stars. This will allow me to ex plore directly the nature and structure of the stellar dynamo that drives this activity. The Doppler Imaging of accretion 'hotspots' will allow me to relate the accretion flows to the field geometry in these stars, and to determine if there is any temporal evolution of these features. Using the reflected light from the inner edge of the circumstellar disc I will be able to perform the first direct tomographic measurement of the disc disruption radius, which will constitute a critical test of the magnetic st ar-disc coupling models. Fields of science natural sciencesmathematicspure mathematicsgeometry Keywords DYNAMO (STELLAR) MAGNETISM (STELLAR) TOMOGRAPHY TTAURISTAR dynamo (stellar) magnetism (stellar) tomography ttauristar Programme(s) FP6-MOBILITY - Human resources and Mobility in the specific programme for research, technological development and demonstration "Structuring the European Research Area" under the Sixth Framework Programme 2002-2006 Topic(s) MOBILITY-2.1 - Marie Curie Intra-European Fellowships (EIF) Call for proposal FP6-2002-MOBILITY-5 See other projects for this call Funding Scheme EIF - Marie Curie actions-Intra-European Fellowships Coordinator CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE EU contribution No data Address Rue Michel Ange 3 PARIS France See on map Total cost No data