发表机构
Maulana Azad National Urdu University; Inter-University Centre for Astronomy and Astrophysics（莫拉纳阿扎德国立乌尔都大学; 大学间天文学与天体物理中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用Gaia DR3和ASteCA建模376个邻近疏散星团，发现中位双星比例恒定（0.29±0.03），与年龄等无关，表明全局双星含量受动力学过程调控，为星团演化模型提供观测约束。
AI 中文摘要
我们利用Gaia DR3数据和基于ASteCA的合成颜色-星等图建模，研究了太阳附近1千秒差距内376个疏散星团的完整样本中未分辨双星比例。双星比例是一个全局光度量，主要对未分辨双星敏感，这些双星会在单星主序上方产生可测量的增宽。我们发现样本的中位双星比例几乎恒定，为$0.29\pm 0.03$，且与星团年龄、核半径、极限半径或中位质量无明显依赖关系。这种表面上的恒定性表明，邻近疏散星团的全局双星含量受竞争性动力学过程调控，包括软双星的瓦解、密近双星的存活与硬化、质量分层、单星蒸发以及长期星团解体。该结果与理论预期及先前观测研究一致，表明星团双星种群可以在内部演化的同时保持相对稳定的全局双星比例。我们的发现为疏散星团形成和动力学演化模型提供了观测约束，并强调了未来结合测光、天体测量、光谱和N体方法以区分原初形成和动力学形成的双星种群研究的必要性。
英文摘要
We investigate the unresolved binary-star fraction in a complete sample of 376 open clusters located within 1 kpc of the Sun using Gaia DR3 and ASteCA based synthetic colour magnitude diagram modelling. The binary fraction is a global photometric quantity, sensitive primarily to unresolved binaries that produce measurable broadening above the single-star main sequence. We find that the median binary fraction of the sample is nearly constant, $0.29\pm 0.03$, with no clear dependence on cluster age, core radius, limiting radius or median mass. This apparent constancy suggests that the global binary content of nearby open clusters is regulated by competing dynamical processes, including disruption of soft binaries, survival and hardening of close binaries, mass segregation, evaporation of single stars, and long-term cluster dissolution. The result is consistent with theoretical expectations and previous observational studies indicating that cluster binary populations can evolve internally while maintaining a relatively stable global binary fraction. Our findings provide an observational constraint for models of open-cluster formation and dynamical evolution and highlight the need for future work combining photometric, astrometric, spectroscopic, and N-body approaches to distinguish between primordial and dynamically formed binary populations.
CommentsAccepted for publication in the Bulletin of the Royal Society of Sciences of Liege
