Habitable Zones

General Relativity Can Prevent a Runaway Greenhouse on Potentially Habitable Planets Orbiting White Dwarfs

By Keith Cowing
Status Report
astro-ph.EP
October 1, 2025
Filed under , , , , , , , , ,
General Relativity Can Prevent a Runaway Greenhouse on Potentially Habitable Planets Orbiting White Dwarfs
Parameter space showing the effect of GR on eccentricity oscillations due to an exterior planetary companion for a variety of combinations of the mass ratio m2/m1 and semi-major axis ratio a2/a1. The interior planet was assumed to be a 1 M⊕ planet at 0.01 AU. When ξ < 1 (bottom-left, red), GR amplifies eccentricity oscillations; when ξ > 1 (top-right, black), GR suppresses them. The dashed line marks the transition as derived in F. C. Adams & G. Laughlin (2006). — astro-ph.EP

Planets orbiting in the habitable zones of white dwarfs have recently been proposed as promising targets for biosignature searches.

However, since the white dwarf habitable zone resides at 0.01 – 0.1 AU, planets residing there are subject to tidal heating if they have any orbital eccentricity.

Previous work (Barnes & Heller 2013) identified nearby planetary companions as potential roadblocks to habitability of planets around white dwarfs, as such companions could induce secular oscillations in eccentricity for the potentially habitable planet, which could in turn heat a surface ocean and induce a runaway greenhouse for even very low values (e∼10−4) of the eccentricity of the potentially habitable planet.

In this work, we examine the potential for general relativistic orbital precession to protect habitable planets orbiting white dwarfs from such a runaway greenhouse, and demonstrate that for some system architectures, general relativity can be protective for planetary habitability.

Eva Stafne, Juliette Becker

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR); General Relativity and Quantum Cosmology (gr-qc)
Cite as: arXiv:2509.26421 [astro-ph.EP] (or arXiv:2509.26421v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2509.26421
Focus to learn more
Related DOI:
https://doi.org/10.3847/1538-4357/ae07c6
Focus to learn more
Submission history
From: Eva Stafne
[v1] Tue, 30 Sep 2025 15:43:33 UTC (2,233 KB)
https://arxiv.org/abs/2509.26421
Astrobiology,

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻