Unveiling the mysteries of stellar dynamics: a pioneering journey in magnetoasteroseismology

Introduction

While stellar evolution has been considered one of the most well-understood astrophysical processes for decades, a massive revolution is in motion thanks to probes of dynamical processes in stellar interiors with asteroseismology. Through this study of stellar oscillations, core rotation-rate measurements point out a very efficient extraction of angular momentum in the depths of stars.

Knowledge Gap

This represents one of the most fundamental, yet poorly understood, processes throughout stellar evolutionary journeys. This critical knowledge gap casts significant doubt on our ability to accurately date astronomical objects in the Universe using current stellar models, as an efficient angular momentum transport would bring fuel to the burning core and therefore extend the life of the star.

Intermediate-Mass Stars

Intermediate-mass stars (IMStars) are the perfect laboratory to elevate our understanding of angular momentum transport in stars. Their structure and internal dynamics resemble that of low-mass stars in the late stages of evolution, as well as high-mass stars during the earliest stages.

Recent Discoveries

The recent discovery of surprising oscillation mode frequencies and amplitudes revealed the presence of stable magnetic fields in the radiative core of a few red giant stars. These fields are similar to those observed at the surface of 10% of IMStars during the preceding phases and later on when they lose their envelope.

Project Aim

The Calcifer ERC project aims at pioneering magnetoasteroseismology through an unprecedented exploration of the evolution of magnetic IMStars. We will use observed stellar oscillations to unlock the invisible, unveiling magnetic processes controlling the dynamics of the plasma in the depths of IMStars along their evolutionary journey.

Ultimate Objective

The ultimate objective of this ambitious and unifying project is to deliver the first meticulously informed model of the magnetized evolution of IMStars from birth to death. This will fundamentally impact our ability to date structures in the Universe.