摘要
锂是少数几种在大爆炸中生成的元素之一，研究锂丰度对于探讨各种元素核合成理论以及星系的早期化学演化规律都具有十分重要的意义。阐述了近期有关恒星（类太阳星、晕族恒星和主序前星）及星团锂丰度的新近观测结果。介绍了在锂的核合成理论研究方面非局部热动平衡效应的影响及锂在恒星演化中的衰竭机制等理论的研究进展和存在的问题．盘族恒星相对年轻，拥有较高的锂丰度，但弥散很大；晕族恒星年老，锂丰度相对盘族恒星偏低，但弥散较小。晕星中锂丰度的Ｓｐｉｔｅ平台仍需进一步的验证。超新星爆发时中微子核合成和大质量ＡＧＢ星是恒星中产生锂的两种最可能的渠道。恒星质量损失、对流超射、微观扩散和自转等都能导致锂的衰竭，但无论哪一种机制都只能解释部分的观测现象。
Lithium is one of the few nuclei which are synthesized during the Big Bang, the abundancesof which are of importance for our understanding of many problems, ranging from primordialnucleosynthesis, to the chemical evolution of our Galaxy. We summarized the recent observationalresults of lithium abundance in solar-like stars, halo stars, pre-main sequence stars and stars incluster. We also presellts here Non-LTE effects on analysing lithium abundance and some lithiumdepletion meChanisms. Disk stars are relatively young and have a high lithium abundance witha large scatter, while the old halo stars have relatively low lithium abundance with a smalldispersion. Whether Spite plateau is real or not is still in discussion. Both supernovae and massiveAGB are the main sources of lithium production in stars. The available depletion mechallisms,such as mass loss, convective overshooting, microscopic diffusion and rotational mixing, can onlyexplain part of the observations.
出处
《天文学进展》
CSCD
北大核心
1999年第4期324-333,共10页
Progress In Astronomy
关键词
恒星
锂丰度
锂衰竭
恒星质量
stars: lithium abundance
stars: lithium depletion
