Cool Stars 14 - Submitted Abstract # 292
This version created on 05 October 2006

Magnetic topologies of cool stars


Jean-Francois Donati, CNRS/Obs Midi-Pyrenees

Stellar magnetic fields can be investigated using several, very
complementary approaches.  While conventional spectroscopy is capable
of estimating the average magnetic strength of potentially complex
field configurations thanks to its low sensitivity to the vector
properties of the field, spectropolarimetry can be used to map the
medium- and large-scale structure of magnetic topologies.  In
particular, this second approach allows one to retrieve information
about the poloidal and toroidal components of the large-scale dynamo
fields in low-mass stars, and thus to investigate the physical
processes that can produce them.  Similarly, this technique can be
used to investigate how magnetic fields couple young stars to their
massive accretion disc and thus to estimate how much angular momentum
is transfered to/extracted from the newly-born low-mass star.  I will
present the latest results in this field obtained with
spectropolarimetry, with special emphasis on very-low mass
fully-convective stars as well as on classical T Tauri stars.  

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