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Almost all massive stars end their lives as supernovae and form a black hole or neutron star, which consequently drive galactic evolution. However there are currently large uncertainties pertaining to massive star interiors already during the main sequence, such as their interior mixing and rotation. Asteroseismology of gravity waves in massive stars provides a unique insight of the physics beneath their opaque surface layers. All massive stars are predicted to excite gravity waves from core convection and from turbulent pressure fluctuations in their near-surface layers, which are extremely efficient at transporting angular momentum and mixing within stellar interiors. On the other hand, spectroscopy provides detailed constraints on the physics of stellar atmospheres, and reveals the importance of increasing macroturbulent broadening in the spectral lines of more massive stars. In this talk, I will discuss recent results based on the combination of high-precision TESS space photometry and high-resolution spectroscopy of massive stars. A clear relationship is found between the location of a massive star in the Hertzsprung-Russell diagram and the amplitudes and frequencies of stochastic photometric variability caused by gravity waves in the light curves of massive stars. Furthermore, the properties of the stochastic variability are strongly correlated with macroturbulent broadening in the spectral lines of massive stars. The common ensemble morphology for the stochastic low-frequency variability detected in TESS photometry and its relationship to macroturbulence is strong evidence for gravity waves being a plausible mechanism for macroturbulence in massive stars, as such waves are unique in providing the dominant tangential velocity field required to explain the observed spectroscopy. Finally, I will discuss the important similarities and differences between magnetic and non-magnetic massive stars in terms of their gravity wave signatures and measured macroturbulent velocities., {"references":["Bowman, D. M., et al. 2019, A&A, 621, A135","Bowman, D. M., et al. 2019, NatAs, 3, 760","Bowman, D. M., et al. 2020, A&A, 640, A36"]}

The evolution of high mass stars (>8M_sun) is strongly dictated by their interior structure, specifically the mixing processes near the core and in the surrounding envelope. Asteroseismology can open up these stellar interiors but unfortunately Kepler did not provide any high-mass stars with identified modes for this endeavour. The TESS space mission is remedying this by observing a large number of high-mass stars allowing us to construct an asteroseismic sample of OB pulsators and open up the way to their asteroseismic sounding. In this poster we present a detailed analysis of the high-mass pulsator HD192575 (B0.5 V) using its 1-year TESS light curve. HD192575 is among the first of its variability class to be observed uninterruptedly during such a long time and the resulting high frequency precision of the measured pulsations allows for in-depth modelling. In our novel modelling strategy we use a maximum likelihood estimator which incorporates correlations among the parameters and theoretical uncertainties due to unknown input physics of stellar models. This allows us to derive a precise mass, internal mixing, and age from zonal modes, as well as its interior rotation from detected rotationally split multiplets of low-degree modes.

We present the discovery of three new $��$ Cep pulsators, three new pulsators with frequency groupings, and frequency patterns in a B3Ib star, all of which show pulsations with frequencies as high as about 17 d$^{-1}$, with K2 space mission photometry. Based on a Fourier analysis and iterative pre-whitening we present a classification and evaluate the potential for asteroseismic modelling. We include the lists of pulsation frequencies for three new $��$ Cep pulsators, CD-28 12286, CD-27 10876, LS 3978, and additional pulsation mode frequencies for the known $��$ Cep pulsator HD 164741. In addition we characterise the regular frequency spacing found in the new pulsator HD 169173, and discuss its origin. We place the newly discovered variables in a colour-magnitude diagram using parallaxes from Gaia-DR2, showcasing their approximate location in the massive star domain. The identified frequency lists of these multiperiodic pulsators are a good starting point for future forward seismic modelling, after identification of at least one pulsation frequency from high-resolution time series spectroscopy and/or multi-colour photometry., Accepted for publication in MNRAS, 18 pages, 12 figures, 11 tables

This white paper focuses specifically on the transport of chemical elements and of angular momentum in the stellar structure and evolution models of stars born with convective core, as revealed by their gravity- mode oscillations.

Context. The lack of high-precision long-term continuous photometric data for large samples of stars has impeded the large-scale exploration of pulsational variability in the OB star regime. As a result, the candidates for in-depth asteroseismic modelling have remained limited to a few dozen dwarfs. The TESS nominal space mission has surveyed the southern sky, including parts of the galactic plane, yielding continuous data across at least 27 d for hundreds of OB stars. Aims. We aim to couple TESS data in the southern sky with ground-based spectroscopy to study the variability in two dimensions, mass and evolution. We focus mainly on the presence of coherent pulsation modes that may or may not be present in the predicted theoretical instability domains and unravel all frequency behaviour in the amplitude spectra of the TESS data. Methods. We compose a sample of 98 OB-type stars observed by TESS in Sectors 1-13 and with available multi-epoch, high-resolution spectroscopy gathered by the IACOB and OWN surveys. We present the short-cadence 2 min light curves of dozens of OB-type stars, which have one or more spectra in the IACOB or OWN database. Based on these light curves and their Lomb-Scargle periodograms, we performed variability classification and frequency analysis. We placed the stars in the spectroscopic Hertzsprung-Russell diagram to interpret the variability in an evolutionary context. Results. We deduce the diverse origins of the mmag-level variability found in all of the 98 OB stars in the TESS data. We find among the sample several new variable stars, including three hybrid pulsators, three eclipsing binaries, high frequency modes in a Be star, and potential heat-driven pulsations in two Oe stars. Conclusions. We identify stars for which future asteroseismic modelling is possible, provided mode identification is achieved. By comparing the position of the variables to theoretical instability strips, we discuss the current shortcomings in non-adiabatic pulsation theory and the distribution of pulsators in the upper Hertzsprung-Russell diagram., With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737)