Discovery of Nine Super Li-rich Unevolved Stars from the LAMOST Survey
Wang, L.; Shi, J. -R.; Zhou, Y. -T.; Yan, T. -S.; Yan, H. -L.; Zhou, Z. -M.; Fang, X. -S.; Li, C. -Q.; Chen, T. -Y.; Xie, X. -J.
China
Abstract
Based on the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) medium-resolution spectroscopic survey (MRS), we report the discovery of nine super Li-rich unevolved stars with A(Li) > 3.8 dex. These objects show unusually high levels of lithium abundances, up to three times higher than the meteoritic value of 3.3 dex, which indicates that they must have experienced a history of lithium enrichment. It is found that seven of our program stars are fast rotators with v sin i > 9 km s-1, which suggests that the accretion of circumstellar matter may be the main contributor to the lithium enhancement of these unevolved stars; however, other sources cannot be excluded.