Orbital stability and secular dynamics of the Proxima Centauri planetary system
Date
2024
Authors
Livesey, Joseph
Barnes, Rory
Deitrick, Russell
Journal Title
Journal ISSN
Volume Title
Publisher
The Astrophysical Journal
Abstract
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.
Description
The authors thank Gongjie Li, Hanno Rein, and Juliette Becker for valuable insights and discussion, and thank the anonymous referee whose thoughtful recommendations substantially improved this manuscript. This work was facilitated through the use of advanced computational, storage, and networking infrastructure provided by the Hyak supercomputer system and funded by the Student Technology Fund at the University of Washington.
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Citation
Livesey, J. R., Barnes, R., & Deitrick, R. (2024). Orbital stability and secular dynamics of the Proxima Centauri planetary system. The Astrophysical Journal, 964(1), 4. https://doi.org/10.3847/1538-4357/ad1ff4