On the Structure and Oscillations of the First Stars

Post-main sequence Population III stars (of the mass range M = 0.8 – 1  MSun) could inhabit dwarf galaxies and the halo of the Milky Way. However, they remain observationally elusive. Surface abundance anomalies induced by evolutionary mixing – particularly thermohaline diffusion and dredge-up events – can mimic the chemical signatures of second-generation stars, complicating spectroscopic identification and mask their primordial nature. In this study, we investigate the potential of asteroseismology to distinguish low-mass Pop III stars from metal-rich counterparts, focusing on seismic observables that are sensitive to their unique internal structures. We perform stellar evolution modeling with MESA and compute oscillation spectra using GYRE, with an emphasis on diagnostics related to properties of the core as well as  core-envelope coupling. With high-cadence photometric data from missions such as PLATO and future surveys, asteroseismology may offer a powerful, non-spectroscopic tool for identifying surviving primordial stars and probing the earliest stages of stellar evolution.