发表机构
University of Hawaii at Mānoa; Academia Sinica Institute of Astronomy and Astrophysics（夏威夷大学马诺阿分校; 中央研究院天文及天文物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出利用恒星表面引力作为年轻恒星（I类至III类）的年龄指示器，通过双星和移动星群验证其可靠性，并证明其不受星周环境干扰。
AI 中文摘要
年轻恒星的年龄难以测量，然而它是理解恒星演化的一个基本属性。在低质量恒星早期阶段，准确的年龄指示器十分稀缺，且往往依赖于星周环境的性质。我们研究了恒星表面引力作为从I类到III类低质量恒星阶段的实用年龄估计器的可行性。当年轻恒星沿林忠四郎轨道下降时，引力单调增加。引力是中心恒星的物理属性，独立于星周环境或演化模型。此外，引力可以对单个天体进行测量。我们对引力作为年龄指示器的可靠性进行了两项测试：（1）年轻双星系统各子星的相对年龄；（2）一个年轻移动星群的相对年龄。我们表明，如果双星是同时形成的，那么年轻双星的引力应一致，这与预期相符。同样，我们在TW Hya星群中发现了相似的引力，并得出其中位年龄为12.8±1.2百万年。在这两种情况下，引力的差异可能反映了年龄的真实差异。我们表明，遮蔽发射与引力之间没有相关性，这表明星周盘发射不会影响我们通过测量光球层恒星引力来推断年龄的能力。
英文摘要
The age of a young star is difficult to measure and yet is a fundamental property that is essential for understanding stellar evolution. Accurate age indicators across the early phases of low-mass stars are scarce and often rely on properties of the circumstellar environment. We investigate stellar surface gravity as a practical age estimator from the class I to the class III phases of low-mass stars. Gravity increases monotonically as young stars descend their Hayashi tracks. Gravity is a physical property of the central star and is independent of the circumstellar environment or evolutionary models. Also, gravity can be measured for individual objects. We performed two tests for the reliability of gravity as an age indicator: (1) the relative ages of the components of young binary stars and (2) the relative ages of a young moving group. We show that young binary stars have consistent gravities, as expected, if they are coeval. Similarly, we find similar gravities among the TW Hya group and derive a median age of 12.8 +/- 1.2 Myr. In both cases, differences in gravities may reflect real differences in the ages. We show that there is no correlation between veiling emission and gravity, showing that circumstellar disk emission does not affect our ability to infer ages from measurements of photospheric stellar gravity.
Comments4 figures, 2 tables
Journal ref2026ApJ...997L..46C
