NGTS星团巡天 - VI：PLATO LOPS2天区内七个年轻疏散星团的恒星自转
NGTS clusters survey - VI: Stellar rotation in seven young open clusters within the PLATO LOPS2 field
浏览论文内容
中文总结 AI 辅助
该研究通过NGTS测量PLATO LOPS2天区七个年轻疏散星团的恒星自转周期，发现40 Myr星团的慢序列可区分，观测到≥1 M⊙恒星自转减速停滞，还给出Alessi 3的新年龄估计。
中文摘要 AI 辅助
我们呈现了NGTS对PLATO首个长凝视LOPS2天区内七个年龄在~40至700 Myr的年轻疏散星团中FGKM型恒星自转周期分布的测量结果。我们测量了1063个自转周期，其中479个是作为星团特异性自转研究的新分析结果，63个是最近TESS全天自转巡天未报告的独特周期。在这1063个自转周期中，有285个通过色-星等图和Gaia天体测量被确认为可能的双星或更高阶多星系统。这些结果是Trumpler 10、NGC 2451B和Alessi 3的首批综合自转周期分布，同时扩展了NGC 2451A、NGC 2516、Collinder 135和IC 2391的现有分布，以更全面地呈现PLATO LOPS2天区内年轻恒星的自转状态。我们发现，年龄约40 Myr的NGC 2451B星团中的主序太阳质量恒星形成了一条慢序列，可与~70-80 Myr的对应恒星区分，从而显著降低了年轻恒星群通过自转序列相对定年的年龄。我们还观测到，在质量≥1 M⊙时，从NGC 2451A的年龄到至少NGC 2516的年龄（~70-150 Myr），自转减速停滞，支持了之前的预测：角动量的重新分布和移除应导致自转减速停滞的波，该波随质量和年龄传播。最后，我们使用微分 gyrochronology 定年法为Alessi 3提供了687±106 Myr的新年龄估计。
英文摘要
We present NGTS measurements of rotation period distributions for FGKM stars in seven young open clusters spanning ~40--700 Myr within PLATO's first long-stare LOPS2 field. We measure 1063 rotation periods, of which 479 are newly analysed as part of cluster specific rotation studies, whilst 63 are unique periods not reported in the recent TESS All-Sky Rotation Survey. Of the 1063 rotation periods, 285 are identified as likely binary or higher order multiple systems using colour-magnitude diagrams and Gaia astrometry. These are the first comprehensive rotation period distributions for Trumpler 10, NGC 2451B and Alessi 3, while extending existing distributions for NGC 2451A, NGC 2516, Collinder 135 and IC 2391, to create a fuller picture on the rotation state of young stars in PLATO's LOPS2 field. We find that main-sequence solar-mass stars in the ~40 Myr old NGC 2451B cluster, form a slow sequence that can be distinguished from their counterparts at ~70--80 Myr, thereby significantly reducing the age at which young stellar groups can be relatively aged via their rotation sequences. We also observe stalled spin down from the age of NGC 2451A to at least that of NGC 2516 (~70--150 Myr) at masses $\gtrsim1$ $M_{\odot}$, supporting previous predictions that angular momentum redistribution and removal should result in a wave of stalled spin down that propagates as a function of both mass and age. Finally, we provide a new age estimate for Alessi 3 of 687$\pm$106 Myr using differential gyrochronology age dating.
