Abstract We examine the performance of standard pre-main-sequence (PMS) stellar evolution models against the accurately measured properties of a benchmark sample of 26 PMS stars in 13 eclipsing binary (EB) systems having masses 0.04–4.0 M ⊙ and nominal ages ≈1–20 Myr. We provide a definitive compilation of all fundamental properties for the EBs, with a careful and consistent reassessment of observational uncertainties. We also provide a definitive compilation of the various PMS model sets, including physical ingredients and limits of applicability. No set of model isochrones is able to successfully reproduce all of the measured properties of all of the EBs. In the H–R diagram, the masses inferred for the individual stars by the models are accurate to better than 10% at ≳1 M ⊙ , but below 1 M ⊙ they are discrepant by 50–100%. Adjusting the observed radii and temperatures using empirical relations for the effects of magnetic activity helps to resolve the discrepancies in a few cases, but fails as a general solution. We find evidence that the failure of the models to match the data is linked to the triples in the EB sample; at least half of the EBs possess tertiary companions. Excluding the triples, the models reproduce the stellar masses to better than ∼10% in the H–R diagram, down to 0.5 M ⊙ , below which the current sample is fully contaminated by tertiaries. We consider several mechanisms by which a tertiary might cause changes in the EB properties and thus corrupt the agreement with stellar model predictions. We show that the energies of the tertiary orbits are comparable to that needed to potentially explain the scatter in the EB properties through injection of heat, perhaps involving tidal interaction. It seems from the evidence at hand that this mechanism, however it operates in detail, has more influence on the surface properties of the stars than on their internal structure, as the lithium abundances are broadly in good agreement with model predictions. The EBs that are members of young clusters appear individually coeval to within 20%, but collectively show an apparent age spread of ∼50%, suggesting true age spreads in young clusters. However, this apparent spread in the EB ages may also be the result of scatter in the EB properties induced by tertiaries.

中文翻译：

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食双星前主序星演化模型的实证检验

摘要 我们针对质量为 0.04-4.0 M ⊙ 且标称年龄 ≈ 的 13 个食双星 (EB) 系统中 26 颗 PMS 恒星的基准样本的准确测量特性，检查了标准前主序 (PMS) 恒星演化模型的性能1–20 密尔 我们提供了 EB 的所有基本属性的明确汇编，并对观测不确定性进行了仔细和一致的重新评估。我们还提供各种 PMS 模型集的最终汇编，包括物理成分和适用性限制。没有一组模型等时线能够成功地重现所有 EB 的所有测量特性。在 H-R 图中，模型推断的单个恒星的质量在 ≳1 M ⊙ 处精确到优于 10%，但在 1 M ⊙ 以下，它们的差异为 50-100%。使用经验关系来调整观察到的半径和温度以了解磁活动的影响有助于解决少数情况下的差异，但无法作为通用解决方案。我们发现有证据表明模型无法匹配数据与 EB 样本中的三元组有关；至少一半的 EB 拥有三级伴侣。不包括三重星，这些模型在 H-R 图中再现了优于约 10% 的恒星质量，低至 0.5 M ⊙ ，低于此值，当前样本完全被三次元污染。我们考虑了几种机制，通过这些机制，三级可能会导致 EB 特性发生变化，从而破坏与恒星模型预测的一致性。我们表明，三次轨道的能量与通过注入热量（可能涉及潮汐相互作用）潜在地解释 EB 特性的散射所需的能量相当。从手头的证据看来，这种机制，无论它如何运作，对恒星表面特性的影响比对内部结构的影响更大，因为锂丰度与模型预测大致相符。属于年轻集群成员的 EB 单独出现在 20% 以内，但总体上显示出约 50% 的明显年龄分布，表明年轻集群中的真实年龄分布。然而，EB 时代的这种明显扩展也可能是由第三纪引起的 EB 特性分散的结果。从手头的证据看来，这种机制，无论它如何运作，对恒星表面特性的影响比对内部结构的影响更大，因为锂丰度与模型预测大致相符。属于年轻集群成员的 EB 单独出现在 20% 以内，但总体上显示出约 50% 的明显年龄分布，表明年轻集群中的真实年龄分布。然而，EB 时代的这种明显扩展也可能是由第三纪引起的 EB 特性分散的结果。从手头的证据看来，这种机制，无论它如何运作，对恒星表面特性的影响比对内部结构的影响更大，因为锂丰度与模型预测大致相符。属于年轻集群成员的 EB 单独出现在 20% 以内，但总体上显示出约 50% 的明显年龄分布，表明年轻集群中的真实年龄分布。然而，EB 时代的这种明显扩展也可能是由第三纪引起的 EB 特性分散的结果。但总体上显示出约 50% 的明显年龄分布，表明年轻集群中的真实年龄分布。然而，EB 时代的这种明显扩展也可能是由第三纪引起的 EB 特性分散的结果。但总体上显示出约 50% 的明显年龄分布，表明年轻集群中的真实年龄分布。然而，EB 时代的这种明显扩展也可能是由第三纪引起的 EB 特性分散的结果。