beta Cep star mode identification

We used grid modelling to gain insights into the population of beta Cep stars. Combining TESS and Gaia, we successfully identified the mode degrees for 148 stars in our sample. We find the majority to have a dominant dipole non-radial mode.

Many non-radial modes show splittings in their TESS frequency spectra, which we used to calculate their envelope rotation, spin parameter, and the level of differential envelope-to-surface rotation. For the last, we find an upper limit of about 3. We also provide relative frequency asymmetries within the multiplets, ranging from -0.15 to 0.15 with most being positive.

Based on grid modelling, we provide mass, convective core mass, and age distributions for 119 stars. Our sample enables asteroseismology of beta Cep pulsators as a population. Our study prepares for future detailed mod- elling based on individual frequencies of identified modes leading towards a better understanding of these massive pulsators.