Ensemble pulsational characteristics of eclipsing binaries containing β Cep stars observed by the TESS mission

Massive pulsators in eclipsing binaries provide precise, model-independent stellar parameters that, combined with asteroseismic constraints, provide powerful probes of internal rotation, convective-core mass, angular-momentum transport, and mixing in massive stars. This study investigates the pulsational characteristics and their impact on the structure and evolution of β Cep pulsators in eclipsing binaries. We analysed an ensemble of 65 β Cep stars in eclipsing binaries, identified rotationally split modes where possible, and statistically derived the dependence of pulsational properties on binary orbital parameters. The interior properties of the systems were also derived using pre-computed grids of stellar structure models with and associated pulsation frequencies using and an asteroseismic routine that tracks the age and rotation of the star in the entire β Cep instability region. MESA StORM Interior rotation rates are derived for 14 systems that exhibit rotational mode splitting. While differential rotation is tentatively inferred for HD 112485, quasi-rigid rotation is found for the primaries of other systems except CZ Vel. Detailed forward asteroseismic modelling was conducted for HD 112485 and EK Cru to deduce their seismic and core properties, as well as their evolutionary state. HD 112485 is one of the least evolved β Cep stars asteroseismically modelled to date, with a core hydrogen mass fraction of X_ c = 0.501_ -0.013 ^ +0.009 . The two reproduced zonal modes in HD 112485 are the first radial-order dipole pressure mode and the second radial-order quadrupole gravity mode, while the zonal modes in EK Cru are the second-order quadrupole mixed mode and the third-order dipole pressure mode. A multivariate regression shows a negative correlation of the pulsation amplitude with pulsation frequency, and no statistically significant relationship with the orbital period. In addition, no significant relationship is observed between the pulsation frequency and the orbital period in the current sample.