Speaker
Description
The physical state of a star is primarily determined by its initial mass and chemical composition, while other factors (e.g. rotation, magnetic fields, companion) play a secondary role. Precise stellar masses are therefore fundamental for constraining stellar structure and evolution (SSE), particularly for rapidly evolving stars more massive than ~1.2 solar masses (i.e. OBAF-type stars). Model-dependent mass estimates - such as spectroscopic and evolutionary masses - remain limited by observational uncertainties and by the simplified one-dimensional treatment of stellar interiors in SSE models. Their precision and accuracy depend both on the number and quality of observational constraints and on our ability to model stellar interiors and evolutionary processes correctly. In contrast, eclipsing double-lined binaries provide model-independent dynamical masses derived directly from orbital dynamics. Systematic discrepancies between dynamical and model-dependent mass estimates comprise the long-standing mass discrepancy problem in stellar astrophysics. This effect has been reported for both single and binary stars, with proposed explanations including binary interaction, rotational mixing, and convective overshooting; however, no single mechanism accounts for all observed cases. Our research investigates the mass discrepancy over a large sample of eclipsing binary systems, enabling an empirical mapping of this effect over a broad parameter space. By identifying the key parameters governing the discrepancy, we aim to formulate the prescriptions for improving state-of-the-art models of stellar structure, evolution, and atmospheres. This objective will be achieved through detailed observational and theoretical modelling of several hundred benchmark systems, targeting mass determinations with precision better than 5%.
| Talk category | NOVA Network 2 |
|---|---|
| PhD relevance | 1st |
