Current problems in stellar evolution

TL;DR

This paper reviews key unresolved issues in stellar evolution modeling, focusing on convection, rotation, and mass loss, and discusses how observations can improve understanding of stellar physics.

Contribution

It provides a comprehensive overview of the main challenges in modeling stellar evolution and explores how observational data can address these uncertainties.

Findings

Convection, rotation, and mass loss are major sources of uncertainty in stellar models.

Observational constraints are crucial for refining theoretical predictions.

Current models face significant challenges in accurately representing internal stellar processes.

Abstract

The theory of stellar evolution plays a central role in astrophysics as stellar models are used to infer properties for Galactic and Extragalactic stellar populations as well as exoplanetary systems. However, despite decades of experience, stellar models still face major issues linked to transport processes of chemicals and angular momentum. This review will focus on some of the processes responsible for the most sizable uncertainties in stellar models such as for example convection, rotation and mass loss. The presentation will discuss their implementation, their impact on theoretical predictions and how various observational constraints can help us gain insight on the physics inside stars and face the current challenges of the theory of stellar evolution.