Exoplanetology: Exoplanets & Exomoons

Secular Perturbations from Exterior Giants Strongly Influence Gap Complexity in Peas-in-a-Pod Exoplanetary Systems

By Keith Cowing
Status Report
astro-ph.EP
January 13, 2025
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Secular Perturbations from Exterior Giants Strongly Influence Gap Complexity in Peas-in-a-Pod Exoplanetary Systems
Factor by which we scale the secular matrix elements when moving or changing the mass of the outer companion. Overlain are KGPS systems from the He & Weiss (2023) analysis containing outer companions and at least three inner planets; cyan triangles denote OG systems while olive triangles denote SC systems. The white stars indicate the averages of these two groups. On average, the scaling factor is ∼ 102 times greater for OG systems than for SC systems in this sample. — astro-ph.EP

It has been demonstrated that systems of tightly packed inner planets with giant exterior companions tend to have less regular orbital spacings than those without such companions.

We investigate whether this observed increase in the gap complexity of the inner systems can be explained solely as the result of secular dynamics caused by the disturbing potential of the exterior companions.

Amplification of mutual orbital inclinations in the inner system due to such secular dynamics may lead to the inner system attaining non-mutually transiting geometries, thereby creating artificial observed gaps that result in a higher calculated gap complexity.

Using second-order secular theory, we compute time-averaged observed gap complexities along a favorable line of sight for a set of hypothetical systems, both with and without an outer giant.

We find that these secular interactions can significantly contribute to the observed gap complexity dichotomy in tightly packed multiple-planet systems.

Joseph R. Livesey, Juliette Becker

Comments: 11 pages, 5 figures. Accepted to ApJ
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2412.18661 [astro-ph.EP] (or arXiv:2412.18661v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2412.18661
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Submission history
From: Joseph Livesey
[v1] Tue, 24 Dec 2024 19:22:57 UTC (2,363 KB)
https://arxiv.org/abs/2412.18661

Astrobiology

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