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arXiv2017

Interpretation of the BRITE oscillation spectra of the early B-type stars: $\nu$ Eri and $\alpha$ Lup

$\nu$ Eridani is a well known multiperiodic $\beta$ Cephei pulsator which exhibits also the SPB (Slowly Pulsating B-type stars) type modes. Recent frequency analysis of the BRITE photometry of $\alpha$ Lupi showed that the star is also a hybrid $\beta$ Cep/SPB pulsator, in which both high and low frequencies were detected. We construct complex seismic models in order to account for the observed frequency range, the values of the frequencies themselves and the non-adiabatic parameter $f$ for the dominant mode. Our studies suggest, that significant modifications of the opacity profile at the temperature range $\log{T}\in (5.0-5.5)$ are necessary to fulfill all these requirements.

astro-ph.SR↗

arXiv2016

Difference frequencies of nonradial pulsation modes and repetitive outbursts in classical Be stars

Space photometry has revealed rich pulsation spectra in classical Be stars. Often frequency pairs can be found that differ by nearly the frequency of a third genuine stellar variability. The lowest currently known of these so-called difference (or $\Delta$) frequencies reach 0.03 c/d, which is the upper limit of outburst frequencies. The potential of such slow variations for pulsation-assisted mass loss is discussed.

astro-ph.SR↗