KIC 3240411 - the hottest known SPB star with the asymptotic g-mode period spacing

TL;DR

This paper reports the discovery and seismic modeling of KIC 3240411, the hottest known SPB star with asymptotic g-mode period spacing, providing insights into its pulsation modes and stellar structure.

Contribution

It presents the first detailed seismic analysis of the hottest hybrid B-type pulsator exhibiting asymptotic g-mode period spacing, including mode identification and evolutionary modeling.

Findings

Dipole axisymmetric modes best fit the observations.

Significant modifications are needed to explain mode instability.

Evolutionary and pulsational models successfully reproduce observed pulsation patterns.

Abstract

We report the discovery of the hottest hybrid B--type pulsator, KIC\,3240411, that exhibits the period spacing in the low--frequency range. This pattern is associated with asymptotic properties of high-order gravity (g) modes. Our seismic modelling made simultaneously with the mode identification shows that dipole axisymmetric modes best fit the observations. Evolutionary models are computed with MESA code and pulsational models with the linear non-adiabatic code employing the traditional approximation to include the effects of rotation. The problem of mode excitation is discussed. We confirm that significant modification is indispensable to explain an instability of both pressure and gravity modes in the observed frequency ranges of KIC\,3240411.