Variability of newly identified B-type stars observed by Kepler

Recent re-determination of stellar atmospheric parameters for a sample of stars observed during the Kepler mission allowed to enlarge the number of Kepler B-type stars. We present the detailed frequency analysis for all these objects. All stars exhibit pulsational variability with maximum amplitudes at frequencies corresponding to high-order g modes. Peaks that could be identified with low-order p/g modes are also extracted for a few stars. We identified some patters in the oscillation spectra that can be associated with the period spacings that can results from the asymptotic nature of the detected pulsational modes. We also tentatively confront the observed oscillation characteristics with predictions from linear non-adiabatic computations of stellar pulsations. For high-order g modes the traditional approximation was employed to include the effects of rotation on the frequency values and mode instability.

Automated summary

Recent re-determination of stellar atmospheric parameters during the Kepler mission has led to the discovery of more Kepler B-type stars. These stars exhibit pulsational variability, with high-order g modes being dominant and some low-order p/g modes also present. Patterns in the oscillation spectra associated with period spacings resulting from the asymptotic nature of the detected pulsational modes have been identified. The observed oscillation characteristics have been tentatively compared to predictions from linear non-adiabatic computations of stellar pulsations, with the effects of rotation on frequency values and mode instability considered for high-order g modes using the traditional approximation.