标题： 前主序双星系统的锂耗尽边界 显示英文标题

标题： Lithium Depletion Boundary in a Pre-Main Sequence Binary System

摘要： 在 HIP 112312（GJ 871.1 A 和 B）中检测到锂丰度降界限，这是一个约 12 Myr 的前主序双星系统。 在次级星（~M4.5）上观察到强的（EW 300 mA）Li 6708 Å 吸收特征，而未在初级星（~M4）上检测到 Li 6708 Å 特征。 通过共同自行运动确认了这两颗恒星的物理伴星关系。 当前的理论前主序演化模型无法同时匹配这一双星系统的观测颜色、亮度和锂耗尽模式。 在 20 Myr 的年龄上限下，当代理论演化模型预测的锂耗尽速度过慢。 如果真实的锂耗尽过程比理论模型预测的更快，则由锂耗尽边界法估算的疏散星团（ Pleiades、alpha Persei 和 IC 2391）的年龄都被高估了。 由于疏散星团年龄标尺的重要性，开发自洽的理论模型以匹配 HIP 112312 的数据是有必要的。 显示英文摘要

摘要： A lithium depletion boundary is detected in HIP 112312 (GJ 871.1 A and B), a \~12 Myr old pre-main sequence binary system. A strong (EW 300 mA) Li 6708 A absorption feature is seen at the secondary (~M4.5) while no Li 6708 A feature is detected from the primary (~M4). The physical companionship of the two stars is confirmed from common proper motions. Current theoretical pre-main sequence evolutionary models cannot simultaneously match the observed colors, brightnesses, and Li depletion patterns of this binary system. At the age upper limit of 20 Myr, contemporary theoretical evolutionary models predict too slow Li depletion. If true Li depletion is a faster process than predicted by theoretical models, ages of open clusters (Pleiades, alpha Persei, and IC 2391) estimated from the Li depletion boundary method are all overestimated. Because of the importance of the open cluster age scale, development of self-consistent theoretical models to match the HIP 112312 data is desirable.