Author:

Abstract:

The theory of stellar structure and evolution is an essential component of astrophysics. Numerous other fields of astrophysics rely on the theoretical models produced by this theory to be accurate. As such, calibrating theoretical models is greatly important. The comparison of predicted model parameters with observed stellar quantities lies at the base of this calibration effort. Intermediate- to high-mass stars are those stars which have a fully mixed convective core during their core-hydrogen burning phase. These stars evolve to produce white dwarfs, neutron stars, and black holes, and provide chemical and dynamical feedback to their environment. The evolution of these stars is driven by the physical properties of the near-core region. However, the implementation of the physical mechanisms at work near the core in theoretical stellar models is un-calibrated. Thus, the results of these un-calibrated physics propagate into any work that relies on the outputs of theoretical stellar models. Efforts to calibrate these models normally rely on the precise determination of stellar quantities through observation. Binary modelling offers the precise determination of the stellar mass and radius to the percent level, providing strong constraining power for stellar models. Alternatively, asteroseismology, or the characterising of stellar interiors through the analysis of observed stellar pulsations, enables the modelling of the core more directly than binarity. In this thesis, we develop a methodology consisting of binary and asteroseismic information to calibrate the implementation of physical mechanisms into stellar models. We address case studies, which serve as proof-of-concept work, as well as larger scale population studies. We apply this methodology to both pulsating and non-pulsating stars in binaries (multiple systems), and clusters to estimate the core masses of intermediate- to high-mass stars. We make use of both ground-based spectroscopy and photometry, as well as space-based photometry to characterise the stars that we study.