标题： 当豌豆在荚中跳动时：恒星聚团如何影响多行星系统中行星属性的观测相关性 显示英文标题

标题： When the Peas Jump around the Pod: How Stellar Clustering Affects the Observed Correlations between Planet Properties in Multi-Planet Systems

摘要： 近期研究表明，行星系统的相邻行星的半径和质量之间存在相关性。 然而，这一“豌豆荚”现象的起源尚不清楚，它是在恒星诞生时就存在还是需要后续演化，以及它最初是否只适用于邻近行星，还是适用于系统内的所有行星。 在这里，我们通过利用最近发现的行星系统结构强烈依赖于周围恒星聚团这一事实来解决这些问题。 基于盖亚任务的第二次数据发布，我们将多行星系统样本分为两类：一类位于恒星位置-速度相空间的过度密集区域，另一类位于背景场中，分别代表受到不同程度外部扰动的样本。 我们证明了“豌豆荚”现象在这两种样本中均存在，这表明系统内行星属性的均匀性不仅限于直接相邻的行星，很可能在行星诞生时就已经存在。 在过度密集区域，半径的均匀性显著增强，这表明它可以被演化效应增强，这些效应要么对整个行星系统产生相似影响，要么有利于保留相似的行星。 质量的均匀性可能表现出类似但较弱的依赖关系。 最后，我们在两种样本中都发现了行星半径和质量向外递增的规律。 尽管这种规律普遍存在，但在过度密集区域它相对较弱，这表明它可能会被来自恒星聚团的外部扰动所破坏。 我们得出结论，“豌豆荚”现象的全面理解需要将行星形成与演化与大规模的恒星和星系环境联系起来。 显示英文摘要

摘要： Recent studies have shown that the radii and masses of adjacent planets within a planetary system are correlated. It is unknown how this 'peas-in-a-pod' phenomenon originates, whether it is in place at birth or requires evolution, and whether it (initially) applies only to neighboring planets or to all planets within a system. Here we address these questions by making use of the recent discovery that planetary system architectures strongly depend on ambient stellar clustering. Based on Gaia's second data release, we divide the sample of planetary systems hosting multiple planets into those residing in stellar position-velocity phase space overdensities and the field, representing samples with elevated and low degrees of external perturbation, respectively. We demonstrate that the peas-in-a-pod phenomenon manifests itself in both samples, suggesting that the uniformity of planetary properties within a system is not restricted to direct neighbors and likely already exists at birth. The radius uniformity is significantly elevated in overdensities, suggesting that it can be enhanced by evolutionary effects that either have a similar impact on the entire planetary system or favour the retention of similar planets. The mass uniformity may exhibit a similar, but weaker dependence. Finally, we find ordering in both samples, with the planet radius and mass increasing outwards. Despite its prevalence, the ordering is somewhat weaker in overdensities, suggesting that it may be disrupted by external perturbations arising from stellar clustering. We conclude that a comprehensive understanding of the 'peas-in-a-pod' phenomenon requires linking planet formation and evolution to the large-scale stellar and galactic environment.