Orbital Stability And Secular Dynamics Of The Proxima Centauri Planetary System

The two innermost planets of the Proxima Centauri system are separated by just 0.02 au, inducing strong gravitational interactions between them.

We assess this interaction by leveraging fast orbital stability indicators and find that orbital stability is very likely if the initial eccentricities of planets b and d are less than ∼0.2, but cannot confirm stability at larger values.

We find that stability is not strongly affected by the true masses of the planets or by the distant planet c. However, mutual inclinations between 95∘ and 142∘ often result in unstable motion. We further explore the long-term evolution of the orbits in these stable regions of parameter space and find that circularization can take over 5 Gyr.

This tidal evolution could support surface energy fluxes in excess of 1 W m−2 for over 1 Gyr, possibly affecting planet b’s habitability.

Secular orbital evolution of Proxima d in each simulated case is displayed in panels (a) and (b), and Proxima b in panels (c) and (d), with the tidal heat flux through the planet b’s surface shown in panel (e). Three simulations end with a tidal heat flux of ∼ 0.1 W m−2 , two end with a near-Earth value of ∼ 0.01 W m−2 , and one with a far lower value. The present tidal heat flux at Io’s and Earth’s surfaces are indicated for reference (Moore et al. 2007; Munk & Wunsch 1998). — astro-ph.EP

Joseph R. Livesey, Rory Barnes, Russell Deitrick

Comments: 15 pages, 7 figures, 4 tables. Accepted for publication in ApJ
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2401.08773 [astro-ph.EP] (or arXiv:2401.08773v1 [astro-ph.EP] for this version)
Submission history
From: Joseph Livesey
[v1] Tue, 16 Jan 2024 19:00:10 UTC (2,278 KB)
https://arxiv.org/abs/2401.08773
Astrobiology,