August 7-10, 2017

Abstract

What have we learnt about B-type main sequence pulsators from the BRITE data

Jadwiga Daszynska-Daszkiewicz (University of Wroclaw, Poland)

Przemys{\l}aw Walczak, Alosha Pamyatnykh and BRITE Executive Science Team Wroclaw University Copernicus Astronomical Center

The discovery of pulsators of the $\beta$ Cep/SPB type has opened up a possibility of getting more stringent constraints on parameters of the model and theory. The simultaneous excitation of pressure and gravity modes offers "touching" stellar regions sensitive to various physical processes. On the other hand, the presence of high order g-modes in massive main sequence stars is the most challenging fact calling for explanation because these modes are stable in all standard-opacity models. Ipso facto, seismic modelling of p/g-mode pulsators is more demanding and more complex and sophisticated approach is needed. Our goal is to draw conclusions about missing components and needed modifications in modelling of the interiors of hot main sequence stars. In particular, we have already shown that in each case, significant modifications of the opacity profile at the depth range $\log{T}\in (5.0-5.5)$ are indispensable to explain all pulsational properties. In this talk, we summarize our previous and current seismic studies of the $\beta$ Cep/SPB pulsators based on the BRITE data. The results of complex seismic analysis for $\nu$ Eri, $\alpha$ Lup, $\theta$ Oph and $\kappa$ Sco are presented. We recall also our results for the two other hybrid pulsators, 12 Lac and $\gamma$ Peg, whose analysis is based on the ground-based observations and the MOST data, respectively. Up to now, one of the most important lessons from the analysis of the BRITE data seems to be that hybrid B-type pulsators are rather a rule that an exception.

Mode of presentation need to be confirmed by the SOC