CFHT UM2025 - Presentation Details
Abstract Details
Title: Magneto-asteroseismology of hot stars
Presenter: Coralie Neiner
Abstract:
Magnetic fields play a crucial role during the entire life of hot stars: they impact their birth, structure, rotation, pulsation, atmosphere, environment, binarity, evolution, and death, and thus next generations of stars and planets and galactic evolution. However, while our understanding of the surface magnetic properties has grown tremendously over the last decades thanks in particular to observations with ESPaDONS at CFHT, difficulties in correctly accounting for the effects of magnetic fields lead to large uncertainties in stellar evolution theory. Asteroseismology is the only existing technique for directly probing stellar interior processes, achieved via precise measurements of stellar pulsations. Magnetic field acts as a perturbation to the pulsation frequencies and lifts the degeneracy of different azimuthal orders into frequency multiplets. This enables the effective pulsation mode identification necessary for asteroseismic modeling, but also allows for a direct measurement of the magnetic field strength inside the star. The novel application of magneto-asteroseismology, i.e. combining asteroseismology and spectropolarimetry, thus provides crucial constraints on the physical ingredients of hot stars and on their evolutionary models. I will review the state-of-the art in magneto-asteroseismology of hot stars, recent progress in this field thanks to ESPaDOnS observations and new tools, and present the Wenaokeao project we propose as part of the 'Amakihi community survey proposal.