标题： NGC 2516疏散星团500秒差距晕的旋转和锂确认 显示英文标题

标题： Rotation and Lithium Confirmation of a 500 Parsec Halo for the Open Cluster NGC 2516

摘要： 最近对盖亚数据的分析已经识别出围绕附近疏散星团的弥散恒星种群。 验证这些“晕”、“尾”和“链”是否与星团较密集部分的恒星具有相似的年龄和组成非常重要。 我们对NGC 2516（$\approx$150 Myr）进行了分析，该星团具有经典的潮汐半径10 pc，并且有一个跨度为500 pc的明显晕（$20^\circ$在天空上）。 结合盖亚的测光数据、TESS的自转周期数据以及Gaia-ESO和GALAH的锂测量数据，我们发现NGC 2516的晕与星团核心具有相同的年龄。 从星团中心向外250 pc范围内，通过运动学选择的晕成员中三分之二的自转周期与150 Myr的自转年代学年龄一致。 一个对比样本的场星没有这种趋势。 晕中的恒星锂丰度高于场星，并且与恒星自转率和双星分数相关，这在其他年轻的疏散星团中也有过报道。 总的来说，这项工作支持了一个新的范式，即疏散星团的晕通常比其核心更丰富。 我们强调了对光谱调查目标、疏散星团分散以及围绕年轻恒星的行星搜索的影响。 显示英文摘要

摘要： Recent analyses of the Gaia data have identified diffuse stellar populations surrounding nearby open clusters. It is important to verify that these "halos", "tails", and "strings" are of similar ages and compositions as stars in the denser part of the cluster. We present an analysis of NGC 2516 ($\approx$150 Myr), which has a classical tidal radius of 10 pc and an apparent halo of stars spanning 500 pc ($20^\circ$ on-sky). Combining photometry from Gaia, rotation periods from TESS, and lithium measurements from Gaia-ESO and GALAH, we find that the halo of NGC 2516 is the same age as the cluster's core. Two thirds of kinematically selected halo members out to 250 pc from the cluster center have rotation periods consistent with a gyrochronological age of 150 Myr. A comparison sample of field stars shows no such trend. The lithium abundances of stars in the halo are higher than in the field, and are correlated with the stellar rotation rate and binarity fraction, as has been noted in other young open clusters. Broadly speaking, this work supports a new paradigm wherein the halos of open clusters are often more populous than their cores. We highlight implications for spectroscopic survey targeting, open cluster dispersal, and planet searches around young stars.