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arXiv · 1705.04460

Spin dynamics of close-in planets exhibiting large TTVs

J. -B. Delisle·A. C. M. Correia·A. Leleu·P. Robutel
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Abstract

We study the spin evolution of close-in planets in compact multi-planetary systems. The rotation period of these planets is often assumed to be synchronous with the orbital period due to tidal dissipation. Here we show that planet-planet perturbations can drive the spin of these planets into non-synchronous or even chaotic states. In particular, we show that the transit timing variation (TTV) is a very good probe to study the spin dynamics, since both are dominated by the perturbations of the mean longitude of the planet. We apply our model to KOI-227b and Kepler-88b, which are both observed undergoing strong TTVs. We also perform numerical simulations of the spin evolution of these two planets. We show that for KOI-227b non-synchronous rotation is possible, while for Kepler-88b the rotation can be chaotic.

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J. -B. Delisle, A. C. M. Correia, A. Leleu, P. Robutel. 2017-05-12. Spin dynamics of close-in planets exhibiting large TTVs. https://doi.org/10.1051/0004-6361/201730755

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