Global Helioseismology

TL;DR

Helioseismology has profoundly advanced our understanding of the Sun's internal structure, dynamics, and fundamental physics, through high-quality observations and sophisticated inference techniques, serving as a benchmark for stellar models.

Contribution

This review summarizes key inference techniques in helioseismology and highlights its role in solar physics and stellar modeling, emphasizing recent developments and ongoing debates.

Findings

Determined solar photospheric helium abundance.

Precisely located the base of the convective zone.

Validated the importance of microscopic diffusion in stellar radiative regions.

Abstract

Helioseismology is one of the most successful fields of astrophysics. The observation and characterization of solar oscillation has allowed solar seismologists to study the internal structure and dynamics of the Sun with unprecedented thoroughness. Ground-based networks and dedicated space missions have delivered data of exquisite quality, enabling the development of sophisticated inference techniques. The achievements of the fields count, amongst other, the determination of solar photospheric helium abundance, unacessible to spectroscopic constraints, the precise positioning of the base of the convective zone and the demonstration of the importance of microscopic diffusion in stellar radiative regions. Helioseismology played also a key role in validating the framework used to compute solar and stellar models and played an important role in the so-called solar neutrino problem. In the current era of astrophysics, with the increasing importance of asteroseismology to precisely characterize stars, the Sun still plays a crucial calibration role, acting as a benchmark for stellar models. With the revision of the solar abundances and the current discussions related to radiative opacity computations, the role of the Sun as a laboratory of fundamental physics is undisputable. In this brief review, I will discuss some of the inference techniques developed in the field of helioseismology, dedicated to the exploitation of the solar global oscillation modes.