Asteroseismology of 16 Kepler Solar-like Stars:Stellar Parameters and the Effects of Element Diffusion  

作　　者：Shuai Wang Qian-Sheng Zhang 

机构地区：[1]Yunnan Observatories,Chinese Academy of Sciences,396 Yangfangwang,Guandu District,Kunming 650216,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Center for Astronomical Mega-Science,Chinese Academy of Sciences,Beijing 100101,China [4]Key Laboratory for the Structure and Evolution of Celestial Objects,Chinese Academy of Sciences,Kunming 650216,China [5]International Centre of Supernovae,Yunnan Key Laboratory,Kunming 650216,China

出　　处：《Research in Astronomy and Astrophysics》2023年第7期206-220,共15页天文和天体物理学研究(英文版)

基　　金：Funding for Yunnan Observatories is co-sponsored by the National Key R&D Program of China(Grant No.2021YFA1600400/2021YFA1600402);the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB 41000000);the National Natural Science Foundation of China(Grant Nos.1177064 and 12133011);the Foundation of the Chinese Academy of Sciences(Light of West China Program and Youth Innovation Promotion Association);the Yunnan Ten Thousand Talents Plan Young and Elite Talents Project;International Centre of Supernovae,Yunnan Key Laboratory(No.202302AN360001)。

摘　　要：Element diffusion has small but significant effects on the structure of the stellar interior.It is interesting to investigate the effects of element diffusion using asteroseismology.We have constructed two grids of stellar models,one with diffusion and one without,for solar-like stars with masses between 0.9 and 1.4 solar masses,and varied initial helium abundance and metallicity.The oscillation frequencies of all stellar models have also been calculated.Piecewise Hermite cubic polynomials are adopted to interpolate stellar p-mode frequencies at an arbitrary age on a stellar evolutionary track.We have investigated 16 Kepler solar-like stars by comparing the model frequencies with observations.The suggested ranges of stellar parameters and some global variables are obtained.For all stars,the best model reproduces the observational frequencies with aχ^(2)of the order of unity.It has been found that element diffusion is important in modeling solar-like stars.Without diffusion,the best value of the initial helium abundance is below the primordial helium abundance from Big Bang nucleosynthesis.When diffusion is taken into account,the required initial helium abundance increases to be higher than the primordial abundance.Diffusion also generally improves the frequency fitting results by reducing the minimum ofχ^(2).Investigation of the second difference of the oscillation frequencies on KIC 8694723 and KIC 10454113 indicates that the current model of element diffusion may underestimate the strength of settling.

关 键 词：ASTEROSEISMOLOGY DIFFUSION stars:interiors stars:abundances 

分 类 号：P144[天文地球—天体物理]