7th June 2021: Calibration of the evolution and structure of intermediate-mass stars with gravity-mode asteroseismology

Speaker: Timothy van Reeth (KU Leuven, Belgium). Location: Virtually; 3 pm

Stellar structure and evolution theory is the backbone of much research in astrophysics. However, many aspects of stars are still not well-understood. Asteroseismology, the study of stellar structure and evolution via the analysis of stellar pulsations, offers us a view into the stellar interior, allowing us to improve and calibrate the theory. Thanks to space missions such as Kepler and now TESS, there has been major progress in the observational study of intermediate- and high-mass main-sequence stars with gravity-mode pulsations, which probe the near-core region. Most notably, we are able to trace the transport of angular momentum and chemical elements that takes place inside these stars. Measured stellar rotation rates and radial rotation profiles have confirmed earlier findings that the theory of angular momentum (AM) transport is incomplete. There are indications that the observed g-mode pulsations themselves may be responsible for (part of) the missing AM transport. In addition, multiple attempts are undertaken to constrain the various chemical transport processes in these stars, including the near-core mixing, the atomic diffusion and the rotation-induced mixing. While we are currently (mostly) limited to one-dimensional stellar models, these results open up the possibility to, in future, calibrate higher-dimensional stellar models as well, properly accounting for effects such as the stellar rotation.

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