期刊
ASTRONOMY & ASTROPHYSICS
卷 584, 期 -, 页码 -出版社
EDP SCIENCES S A
DOI: 10.1051/0004-6361/201527337
关键词
stars: fundamental parameters; stars: abundances; stars: individual: KIC 9821622; stars: chemically peculiar; stars: late-type; techniques: spectroscopic
资金
- CONICET
We report the discovery of a new exceptional young lithium-rich giant, KIC 9821622, in the Kepler field that exhibits an unusually large enhancement of alpha, Fe-peak, and r-process elements. From high-resolution spectra obtained with GRACES at Gemini North, we derived fundamental parameters and detailed chemical abundances of 23 elements from equivalent widths and synthesis analysis. By combining atmospheric stellar parameters with available asteroseismic data, we obtained the stellar mass, radius, and age. The data analysis reveals that KIC 9821622 is a Li-rich (A(Li)(NLTE) = 1.80 +/- 0.2) intermediate-mass giant star (M = 1.64 M-circle dot) located at the red giant branch near the luminosity bump. We find unexpectedly elevated abundances of Fe-peak and r-process elements. In addition, as previously reported, we find that this is a young star (2.37 Gyr) with unusually high abundances of alpha-elements ([alpha/Fe] = 0.31). The evolutionary status of KIC 9821622 suggests that its Li-rich nature is the result of internal fresh Li that is synthesized through the Cameron-Fowler mechanism near the luminosity bump. However, its peculiar enhancement of alpha, Fe-peak, and r-process elements opens the possibility of external contamination by material enriched by a supernova explosion. Although it is less likely, planet accretion cannot be ruled out.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据