Presentation 1 : Oral
Atmospheric dynamics in pulsating stars
Merieme Chadid, Philippe Mathias and Denis Gillet
The pulsating variable stars are still not well understood, especially,
their atmospheric structure. We present the first detection of a
frequency multiplet in the line profile variations which provides a
strong indication for the presence of nonradial pulsations in these
stars. We show, for the first time, hypersonic shock waves propagating
throughout the stellar atmosphere and their intaraction with the
turbulence and the magnetic field in these stars.
Presentation 2 : Poster
Asterosismology of gamma Doradus stars: COROT Additional Programs
P. Mathias, M. Chadid, E. Chapellier, J.-M. Le Contel, J.-P. Sareyan, J.-C. Valtier
Gamma Doradus stars form a new class of variables in between the Sun and the Cepheid Instability Strip, in which gravity modes are currently observed. We present here the first spectroscopic results of an international multisite multitechnique campain concerning These stars with the aim of selecting the best candidate(s) for a proposal for COROT Additional Programs. Indeed, while the COROT core programs concern mainly pressure mode pulsators, gravity-mode stars are interesting because the most internal layers are best probed.