论文标题
在开放簇中的中间到低质量星星和李的演变
Intermediate-to-Low Mass Stars in Open Clusters and the Evolution of Li
论文作者
论文摘要
1-3 Gyr Age的开放簇（OC）包含与理解LI进化的多个相关性的进化阶段中间到低质量的星星。从固定年龄的锂浸（LD）的热侧离开主序列（MS）的恒星可以包括一系列质量，不同程度的核心退化性和在静态或闪光条件下的氦点火。对关键开放群集中从巨型分支到LD下方的大量恒星样本的持续调查揭示了对不同质量和年龄恒星之间LI差异来源的关键线索的模式。尽管LD在这个时代的OC中已经建立了很好的确定，但LD热的恒星可以表现出LI范围从明显的原始簇值到与LD中心相似的上限，尽管占据了与LD中心相似的区域，尽管占据了颜色数字图的相同区域（CMD）。第一个巨大的巨人分支上的恒星显示可衡量的LI急剧下降，与年龄增加和下结为减少的质量密切相关。我们讨论如何在LD本身的存在以及单个恒星的时间演变的背景下解释这些趋势。
Open clusters (OC) of 1-3 Gyr age contain intermediate-to-low-mass stars in evolutionary phases of multiple relevance to understanding Li evolution. Stars leaving the main sequence (MS) from the hot side of the Lithium dip (LD) at a fixed age can include a range of mass, varying degrees of core degeneracy, and helium ignition under quiescent or flash conditions. An ongoing survey of a significant sample of stars from the giant branch to below the LD in key open clusters has revealed patterns that supply critical clues to the underlying source of Li variation among stars of differing mass and age. While the LD is well established in OC of this age, stars on the hot side of the LD can exhibit Li ranging from the apparent primordial cluster value to upper limits similar to those found at the LD center, despite occupying the same region of the color-magnitude diagram (CMD). Stars on the first-ascent giant branch show a dramatic decline in measurable Li that correlates strongly with increasing age and reduced turnoff mass. We discuss how these trends can be explained in the context of the existence of the LD itself and the temporal evolution of individual stars.
