![Atmospheric and water loss of an Earth-like planet for three stellar systems: (e,f) M-dwarf (TRAPPIST-1) central habitable zone. The mass losses shown in a,b,c and d are after 6 Gyr of system integration. -- Full chart below [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Simulated-Effects.png?fit=1200%2C676&ssl=1)
[astro-ph.EP] Thousands of exoplanets have been discovered in recent decades, yet Earth remains the only known world with life.
To assess the potential habitability of other planets, we must identify the importance of various physical conditions that may contribute to sustaining life. One such factor is the presence of a planetary magnetic field. A planet’s magnetic field can protect its atmosphere from photoevaporation, and its long-term strength depends on interior heat flow driven by radiogenic heating from isotopes such as 40K, 232Th, 235U, and 238U.
In this work, we use the VPLanet code to simulate the coupled thermal, magnetic, and atmospheric evolution of Earth-like planets with varying radiogenic heat budgets orbiting G-, K-, and M-dwarf stars.
The range of isotope abundances tested is based on observed stellar elemental distributions for planet-hosting stars in the Milky Way. We find that variations in radiogenic heating slightly extend dynamo lifetimes and reduces atmosphere and surface water loss for K- and G-dwarf systems, while its effects are more negligible for M dwarfs.
Our results show that, while stellar irradiation and planetary location primarily control photoevaporation rates, radiogenic heating contributes to planetary habitability in a small subset of cases and may help refine target selection for future surveys.
Atmospheric and water loss of an Earth-like planet for three stellar systems: (a,b) G-dwarf (Sun) at 1 AU, (c,d) K-dwarf (HD22049) central habitable zone, and (e,f) M-dwarf (TRAPPIST-1) central habitable zone. The mass losses shown in a,b,c and d are after 6 Gyr of system integration. — [astro-ph.EP]
Nathaniel Tanglin, Juliette Becker
Comments: 15 pages, 6 figures, published in the ApJ
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2609.26917 [astro-ph.EP](or arXiv:2609.26917v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2609.26917
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Journal reference: Nathaniel Tanglin and Juliette Becker 2026 ApJ 1008 264
Related DOI:
https://doi.org/10.3847/1538-4357/ae8f2b
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Submission history
From: Nathaniel Tanglin
[v1] Tue, 22 Sep 2026 18:12:48 UTC (2,488 KB)
https://arxiv.org/abs/2609.26917
Astrobiology, exoplanet,
