Recently, there have been advancements in the study of the internal structure of stars by the Stellar Physics Group of Yunnan Observatories, Chinese Academy of Sciences (CAS) through asteroseismology. The results have been published in ApJ (Astrophysical Journal). This research utilized asteroseismic data from a main-sequence star named KIC 10526294, which has a mass approximately three times that of the Sun, to explore convective overshooting and internal chemical abundance structures in stars.

Asteroseismology is a popular discipline in current stellar physics, which combines stellar evolution theory with observations of stars' vibrations to investigate their internal structures. By comparing the theoretical frequencies of stellar evolution models with observed frequencies, fundamental stellar parameters can be obtained, leading to constraints on stellar structure and internal physical processes.

ZHANG et al. established models of star KIC 10526294 with different convective overshooting parameters, taking into account the rapid decay behavior of the convective overshooting diffusion coefficient near the convective boundary. This behavior was a theoretical prediction from the authors' earlier convective overshooting model (ZHANG 2013). By comparing the oscillation periods of different parameter stellar models with observations, it was found that the best agreement between observation and theoretical models occurs when the convective overshooting diffusion coefficient decays rapidly by about four orders of magnitude near the convective boundary. Consequently, this research supports the authors' earlier convective overshooting theoretical model. The results imply that turbulent transport processes for dynamical and thermodynamic quantities in the convective overshooting region have different characteristic lengths, supporting the idea of wave-dominated features in the convective overshooting zone, providing crucial clues for the development of theories related to stellar convection and turbulence.

Furthermore, the paper studied the variations in g-mode oscillation periods when small disturbances occur in the stellar structure. They derived a concise quantitative formula, which can be conveniently used to address deficiencies in models exploring stellar structure using g-mode oscillations. The oscillation period intervals of KIC 10526294 contain an oscillatory component, and using this formula, the study found that this component corresponds to a chemical abundance anomaly within the star's interior that was not considered in the theoretical model. This discovery provides a unique object for improving stellar structure evolution models.

This work is co-sponsored by the National Key R&D Program of China, the Strategic Priority Research Program of the Chinese Academy of Sciences, the National Natural Science Foundation of China, the Foundation of the Chinese Academy of Sciences (Light of West China Program and Youth Innovation Promotion Association), and International Centre of Supernovae, Yunnan Key Laboratory.

Contact:
ZHANG Qiansheng
Yunnan Observatories, CAS
Email: zqs@ynao.ac.cn