Study Examines How Stellar Mixing Affects Asteroseismic Signatures in Mass-Accreting Binary Stars
A new parameter study published on arXiv and accepted by Monthly Notices of the Royal Astronomical Society investigates how different near-core mixing assumptions affect the asteroseismic properties of massive stars that have accreted mass from a binary companion. The research uses one-dimensional stellar structure and evolution models to test the robustness of previously identified seismic imprints of mass accretion, finding that convective boundary mixing dominates over semiconvective mixing in shaping post-accretion stellar structure. The findings matter because binary interactions are now known to be extremely common in intermediate- and high-mass star systems, making accurate asteroseismic diagnostics essential for understanding stellar evolution.
Researchers led by Jan Henneco have conducted a parameter study exploring how assumptions about near-core mixing — particularly semiconvection and convective boundary mixing — influence the asteroseismic signatures of early-type main-sequence stars that have gained mass through binary interactions. Using one-dimensional stellar structure and evolution models, the study finds that convective boundary mixing is the dominant factor controlling both stellar rejuvenation and post-accretion asteroseismic properties, while variations in semiconvective mixing efficiency have comparatively little effect on the recovered seismic imprint. A key result is that post-accretion thermal relaxation plays a critical role in determining the final near-core structure and the resulting asteroseismic signal. The study also reaffirms the utility of Fourier transforms of period spacing patterns as a tool for distinguishing the effects of different mixing and accretion-rate assumptions. The authors note that the asteroseismic imprint is sensitive not only to stellar structure and evolution modelling choices but also to the specifics of accretion physics. The paper, spanning 16 pages plus an 8-page appendix with 22 figures and 2 tables, was accepted by MNRAS on June 7, 2026, and the authors identify a multi-dimensional parameter study incorporating both single- and binary-star assumptions as the logical next step.
What's missing
The study is limited to one-dimensional stellar models, which cannot capture multi-dimensional hydrodynamic effects of accretion and mixing. The parameter space explored is not fully comprehensive — the authors themselves identify a broader multi-dimensional parameter study, including single-star comparisons, as future work.
What different sources said
- arXiv astro-phCenter
The effect of near-core mixing on rejuvenation and the asteroseismic properties of massive accretors
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