发表机构
Federal Institute of Education, Science and Technology of Alagoas (IFAL); Group of Orbital & Rotational Research in Irregular Objects & Observational astroNomy (ORION), Unesp; Group of Orbital Dynamics & Planetology, São Paulo State University (Unesp), School of Engineering and Sciences（阿拉戈阿斯联邦教育、科学和技术学院; 不规则天体轨道与旋转研究及观测天文小组（ORION），圣保罗州立大学; 圣保罗州立大学（Unesp）工程与科学学院轨道动力学与行星学小组）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究结合S/2025 U1的纳入、三颗卫星的修正质量及更新带谐系数，通过数值积分等方法分析天王星内卫星系统，发现S/2025 U1轨道稳定，R=7公里时可局部稳定系统，还确定了附近假设卫星的稳定范围，同时指出四颗卫星对更新参数敏感。
AI 中文摘要
我们结合三项最新进展研究天王星内卫星系统的动力学：纳入新卫星S/2025 U1、Cordelia、Ophelia和Cressida的修正质量估计，以及更新的带谐系数（J₂、J₄和J₆）。通过数值积分、平均运动共振分析和频率映射分析（FMA），我们探究这些因素对轨道稳定性的影响。我们首次分析新发现卫星S/2025 U1的动力学，发现其轨道稳定，在25万年的时间跨度内轨道要素呈现平滑变化。根据采用的半径，S/2025 U1对周边区域的引力影响更符合半径约5-7公里天体的特征，产生与规则轨道演化相关的扩散映射。此外，R=7公里的情况显示相邻卫星的扩散减少，表明其可能对系统轨道演化产生局部稳定作用。我们还在其轨道周围识别出低扩散的内外区域，表明该动力学环境符合共轨粒子或额外小卫星的生存条件。相反，极高的半径值，尤其是R=20公里，往往会增加相邻卫星间的扩散，使该情景与动力学稳定轨道结构的契合度较低。我们进一步探究S/2025 U1附近假设卫星的生存情况，结果显示质量达S/2025 U1三倍的天体可在其轨道内侧（S/2025 U1与Ophelia之间）和外侧（S/2025 U1与Bianca之间）保持稳定。最后，Cressida、Desdemona、Juliet和Portia对更新参数最为敏感，多数共振处于循环状态，而Belinda-Perdita的44:43共振以减小的天平动振幅约束着该系统。
英文摘要
We investigate the dynamics of Uranus's inner satellite system considering three recent updates: the inclusion of the new moon S/2025~U1, revised mass estimates for Cordelia, Ophelia, and Cressida, and updated zonal harmonic coefficients (J$_2$, J$_4$, and J$_6$). Using numerical integrations, mean-motion resonance analysis, and Frequency Map Analysis (FMA), we explore their impact on orbital stability. For the first time, we analyze the dynamics of the newly discovered moon S/2025~U1 and find that it follows a stable orbit, exhibiting smooth variations in its orbital elements over 250,000~years. Depending on the adopted radius, the gravitational influence of S/2025~U1 on the surrounding region is more compatible with a body of approximately 5-7 km radius, producing diffusion maps associated with a regular orbital evolution. Furthermore, the case $R = 7$ km shows a reduction in the diffusion of neighboring satellites, suggesting a possible local stabilizing effect on the system's orbital evolution. We also identified inner and outer regions of low diffusion around its orbit, suggesting that the dynamical environment is compatible with survival of coorbital particles or additional small satellites. In contrast, very high radius values, particularly $R = 20$ km, tend to increase diffusion among neighboring satellites, making this scenario less compatible with a dynamically stable orbital configuration. We further explore the survival of hypothetical satellites near S/2025~U1. Our results show that bodies with masses up to $3\times$ that of S/2025~U1 can remain stable in both the interior (between S/2025~U1 and Ophelia) and the exterior (between S/2025~U1 and Bianca) of its orbit. Finally, Cressida, Desdemona, Juliet, and Portia are most sensitive to updated parameters. Most resonances circulate, while Belinda-Perdita 44:43 confines the system with reduced libration amplitude.
Comments18 pages, 15 figures, and 6 tables. Accepted for publication in Section 10 (Planets, planetary systems, and small bodies) of Astronomy & Astrophysics (A&A). Final proof
Journal refAstronomy & Astrophysics (A&A) 2026
DOI：10.1051/0004-6361/202558328
