Bugnet Group

Asterics – Asteroseismology and Stellar Dynamics

Our understanding of the universe from exoplanets characterization to galactic archaeology strongly relies on our understanding of stellar dynamics. It was recently discovered that stellar evolution models that take into account the rotation of the star and associated hydrodynamic transport processes predict a much faster rotation rate than what is observed. Since then, it is of paramount importance to understand how angular momentum is redistributed inside stars, as it could strongly modify our theory of stellar evolution, and thus the estimation of ages in the universe.

In large part, this turnaround was made possible by Asteroseismology, which then became one of the leading methods for the characterization of stars. This recent branch of stellar physics consists of the analysis of oscillations of stars induced by stationary waves. It is the analogue of seismology on Earth, since it allows to probe the internal structure and the dynamics of the body.

The research activities of the Bugnet group aim at understanding the evolution of stars and their dynamical processes thanks to Asteroseismology. Stellar magnetic fields, from the core to the envelope of the star, are at the center of the group’s research. So far, they have largely been excluded from stellar evolution models due to a lack of observation and of theoretical prescriptions. To make the necessary breakthrough on our understanding of poorly characterized but essential stellar magnetic fields, the group brings together in synergy observational constraints from Asteroseismology, modeling of stellar evolution, and theoretical prescriptions.