The solitary g-mode frequencies in early B-type stars

Abstract

We present possible explanations of pulsations in early B-type main sequence stars which arise purely from the excitation of gravity modes. There are three stars with this type of oscillations detected from the BRITE light curves: $κ$ Cen, a Car, $κ$ Vel. We show that by changing metallicity or the opacity profile it is possible in some models to dump pressure modes keeping gravity modes unstable. Other possible scenario involves pulsations of a lower mass companion.

talk at the second BRITE-Constellation Science Conference, Innsbruck, 2016, to be published in the Proceedings of the Polish Astronomical Society, eds: G. Stachowski, E. Poretti, and J. Matthews