AN IMPROVED DETERMINATION OF THE LITHIUM DEPLETION BOUNDARY AGE OF BLANCO 1 AND A FIRST LOOK ON THE EFFECTS OF MAGNETIC ACTIVITY
AN IMPROVED DETERMINATION OF THE LITHIUM DEPLETION BOUNDARY AGE OF BLANCO 1 AND A FIRST LOOK ON THE EFFECTS OF MAGNETIC ACTIVITY
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DOI：
10.1088/0004-637x/795/2/143
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发表时间：
2014-09
期刊：
影响因子：
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通讯作者：
Aaron J. Juarez;P. Cargile;D. James;K. Stassun
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文献类型：
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作者：
Aaron J. Juarez;P. Cargile;D. James;K. Stassun
锂耗尽边界（LDB）是一个可靠的方法，用于准确地确定年轻的星系团的年龄，但大多数用于推导LDB年龄的主序前模型不包括磁活动对恒星性质的影响。有鉴于此，我们提出了我们的光谱研究的结果，非常低质量的成员的南部疏散星团布兰科1使用双子座北望远镜，程序ID：GN-2009 B-Q-53和GN-2010 B-Q-96。我们获得了中等分辨率的双子座多目标摄谱仪光谱的集群候选成员与I-13-20 mag. From我们的样本43光谱，我们发现14个可能的集群成员通过考虑接近集群序列的I/I-Ks色星等图，协议与集群的系统径向速度，和磁活动作为一个年轻的指标。系统分析了Hα和Li特征，将布兰科1的LDB年龄更新为Myr。我们新的布兰科1的LDB年龄显示出与基准的昴星团疏散星团的显著的一致性。利用现有的经验活动校正，我们调查的影响，磁活动的LDB年龄的布兰科1。考虑到活动，我们推断校正后的LDB年龄为百万年。这项工作表明了磁活动对LDB推断的恒星年龄的重要性，这表明需要重新调查以前的LDB年龄测定。
The lithium depletion boundary (LDB) is a robust method for accurately determining the ages of young clusters, but most pre-main-sequence models used to derive LDB ages do not include the effects of magnetic activity on stellar properties. In light of this, we present results from our spectroscopic study of the very-low-mass members of the southern open cluster Blanco 1 using the Gemini-North Telescope, program IDs: GN-2009B-Q-53 and GN-2010B-Q-96. We obtained Gemini Multi-Object Spectrograph spectra at intermediate resolution for cluster candidate members with I ≈ 13–20 mag. From our sample of 43 spectra, we find 14 probable cluster members by considering proximity to the cluster sequence in an I/I − Ks color–magnitude diagram, agreement with the cluster's systemic radial velocity, and magnetic activity as a youth indicator. We systematically analyze the Hα and Li features and update the LDB age of Blanco 1 to be Myr. Our new LDB age for Blanco 1 shows remarkable coevality with the benchmark Pleiades open cluster. Using available empirical activity corrections, we investigate the effects of magnetic activity on the LDB age of Blanco 1. Accounting for activity, we infer a corrected LDB age of Myr. This work demonstrates the importance of accounting for magnetic activity on LDB inferred stellar ages, suggesting the need to reinvestigate previous LDB age determinations.