Séminaire IPAG

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Studying the Magnetic Fields of Cool Stars

jeudi 9 novembre 2023 - 11h00

Stephen Marsden - University of Southern Queensland
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The creation of magnetic fields in cool stars is one of the most important processes operating in such stars, impacting everything from the star’s rotational evolution to the habitability of any orbiting planets. In our Sun, these magnetic fields are generated through a dynamo process driven by convection and differential rotation which creates a 22-year magnetic cycle with rising and falling magnetic activity. But what of other stars? We assume that all cool stars with internal structures similar to the Sun should host some sort of dynamo generated magnetic field, but do they have a magnetic cycle like our own Sun, with changing levels of magnetic activity and polarity reversals? Over the last few decades, techniques such as Zeeman Doppler Imaging (ZDI) have delivered major advances in the observational study of stellar magnetic fields as we can now map global stellar surface magnetic topologies and survey stars of different masses, ages, and rotation rates. Using these surface field maps we can look for changes in stellar magnetic fields akin to the Sun’s magnetic cycle and use these maps to model stellar winds and their impact on exoplanets. In this talk I will give an overview of BCool, an international project looking at the magnetic fields of cool stars, as well as an introduction to the BinaMIcS work I am undertaking in Grenoble looking at the magnetic fields of cool binary stars (modifié)

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Hôtes : Evelyne Alecian

Salle Manuel Forestini, 414 rue de la piscine, 38400 Saint Martin d'Hères