文章基本信息

标题：Cupid is not Doomed Yet: On the Stability of the Inner Moons of Uranus
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作者：Matija Ćuk ; Robert S. French ; Mark R. Showalter 等
期刊名称：The Astronomical journal
印刷版ISSN：0004-6256
电子版ISSN：1538-3881
出版年度：2022
卷号：164
期号：2
页码：1-8
DOI：10.3847/1538-3881/ac745d
语种：English
出版社：American Institute of Physics
摘要：Some of the small inner moons of Uranus have very closely-spaced orbits. Multiple numerical studies have found that the moons Cressida and Desdemona, within the Portia subgroup, are likely to collide in less than 100 Myr. The subsequent discovery of three new moons (Cupid, Perdita, and Mab) made the system even more crowded. In particular, it has been suggested that the Belinda group (Cupid, Belinda, and Perdita) will become unstable in as little as 105 yr. Here we revisit the issue of the stability of the inner moons of Uranus using updated orbital elements and considering tidal dissipation. We find that the Belinda group can be stable on 108 yr timescales due to an orbital resonance between Belinda and Perdita. We find that tidal evolution cannot form the Belinda–Perdita resonance, but convergent migration could contribute to the long-term instability of the Portia group. We propose that Belinda captured Perdita into the resonance during the last episode of disruption and reaccretion among the inner moons, possibly hundreds of Myr ago.