Tidal Dissipation and Synchronization of the Temperate Exo-Earth LP 791-18d

The creep tide theory is used to explore several aspects of the tidal evolution of the planetary system of the M-star LP 791-18.
We discuss the early synchronization of the exo-Earth LP 791-18d and show that the trapping of its rotation in a 3:2 spin-orbit resonance would only have been possible if its eccentricity were approximately 0.04 or larger.
The planet is likely in synchronous rotation. The perturbations of the other planets in the system do not allow the complete damping of the orbital eccentricity, and the resulting mechanical energy balance indicates that the tidal energy dissipated inside the planet may flow through the planetary surface at approximately 1 watt per square meter.
Sylvio Ferraz-Mello, Thayná Menezes Bechara, Raphael Alves-Silva
Comments: 15 pages, 7 figures. To be published in European Physical Journal Special Topics
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
MSC classes: 37N05
Cite as: arXiv:2506.13621 [astro-ph.EP] (or arXiv:2506.13621v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2506.13621
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Submission history
From: Sylvio Ferraz-Mello
[v1] Mon, 16 Jun 2025 15:49:16 UTC (240 KB)
https://arxiv.org/abs/2506.13621
Astrobiology,