The internal rotation profile of the B-type star KIC10526294 from frequency inversion of its dipole gravity modes and statistical model comparison

TL;DR

This study uses asteroseismology and frequency inversion techniques on Kepler data to map the internal rotation profile of the B-type star KIC 10526294, revealing potential differential rotation and improving understanding of stellar evolution.

Contribution

It introduces four approaches to interpret rotational splittings and constrains the internal rotation profile of a massive star using seismic data.

Findings

Core-envelope boundary rotation rate is approximately 163±89 nHz.

Data are consistent with rigid rotation but suggest possible counter-rotation.

Seismic models can resolve differential rotation with small observational errors.

Abstract

The internal angular momentum distribution of a star is key to determine its evolution. Fortunately, the stellar internal rotation can be probed through studies of rotationally-split non-radial oscillation modes. In particular, detection of non-radial gravity modes (g modes) in massive young stars has become feasible recently thanks to the Kepler space mission. Our aim is to derive the internal rotation profile of the Kepler B8V star KIC 10526294 through asteroseismology. We interpret the observed rotational splittings of its dipole g modes using four different approaches based on the best seismic models of the star and their rotational kernels. We show that these kernels can resolve differential rotation the radiative envelope if a smooth rotational profile is assumed and the observational errors are small. Based on Kepler data, we find that the rotation rate near the core-envelope boundary is well constrained to $163\pm89$ nHz. The seismic data are consistent with rigid rotation but a profile with counter-rotation within the envelope has a statistical advantage over constant rotation. Our study should be repeated for other massive stars with a variety of stellar parameters in order to deduce the physical conditions that determine the internal rotation profile of young massive stars, with the aim to improve the input physics of their models.