Seismic probe of transport processes in red giants

TL;DR

This paper reviews how seismic data from space telescopes has advanced understanding of red giant internal processes, highlighting current limitations in modeling mixing and angular momentum evolution.

Contribution

It discusses recent seismic diagnostics of mixing and angular momentum in red giants, emphasizing the gaps in current theoretical models.

Findings

Seismic data has improved characterization of red giants' internal properties.

Current models still lack accurate representation of mixing beyond the convective core.

Understanding of angular momentum evolution in post-main sequence stars remains incomplete.

Abstract

Seismic data obtained with the space photometric CoRoT and Kepler instruments have led to a unprecendently precise characterization -- in terms of masses and ages -- of a large sample of post main sequence stars (low mass subgiant and red giants). The high quality of the collected seismic data and the subsequent theoretical work for interpreting them brought up a series of issues which revealed that our knowledge of the internal properties of red giant stars remains quite limited. Two such important issues are discussed here, namely mixing beyond the convective core of helium burning red giant stars and evolution of internal angular momentum for post main sequence stars. This includes how they were diagnosed and what are the resulting improvements in our understanding regarding these issues (or rather how far we are from a proper understanding and realistic modelling of the structure and evolution of post main sequence stars).