GRIT: a package for structure-preserving simulations of gravitationally interacting rigid-bodies

Abstract

Spin-orbit coupling of planetary systems plays an important role in the dynamics and habitability of planets. However, symplectic integrators that can accurately simulate not only how orbit affects spin but also how spin affects orbit have not been constructed for general systems. Thus, we develop symplectic Lie-group integrators to simulate systems consisting gravitationally interacting rigid bodies. A user friendly package (GRIT \url{https://github.com/GRIT-RBSim/GRIT}) is provided and external forcings such as tidal interactions are also included. As a demonstration, this package is applied to Trappist-I. It shows that the differences in transit timing variations due to spin-orbit coupling could reach a few min in ten year measurements, and strong planetary perturbations can push Trappist-I f, g and h out of the synchronized states.

arXiv comment18 pages, 12 figures. Accepted for publication in ApJ

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Cited by in corpus (7)

• Self-Consistent Spin, Tidal and Dynamical Equations of Motion in the REBOUNDx Framework
• A Note on the Construction of Explicit Symplectic Integrators for Schwarzschild Spacetimes
• Sporadic Spin-Orbit Variations in Compact Multi-planet Systems and their Influence on Exoplanet Climate
• A direct N-body integrator for modelling the chaotic, tidal dynamics of multi-body extrasolar systems: TIDYMESS
• Were the Obliquities in DI Herculis Excited by an Unseen Tertiary Companion?
• Low Spin-Axis Variations of Circumbinary Planets
• NySALT: Nyström-type inference-based schemes adaptive to large time-stepping