The observed ‘radius valley’ — a dip in the distribution of exoplanet radii, which separates rocky super-Earths from larger sub-Neptunes — is at odds with current theories of planetary formation. New simulations that couple planet formation and evolution, and account for the orbital migration of planets that are largely composed of steam, are able to reproduce the valley feature.
References
Baruteau, C. et al. Planet-disk interactions and early evolution of planetary systems. In Protostars and Planets VI (eds Beuther, H., Klessen, R. S., Dullemond, C. P. & Henning, T.) 667–689 (Univ. Arizona Press, 2014). This review article covers the mechanism that causes orbital migration.
Fulton, B. J. & Petigura, E. A. The California-Kepler survey. VII. Precise planet radii leveraging gaia dr2 reveal the stellar mass dependence of the planet radius gap. Astron. J. 156, 264–276 (2018). This paper reports the updated statistics of the radius valley used as a comparison in our study.
Owen, J. E. Atmospheric escape and the evolution of close-in exoplanets. Annu. Rev. Earth Planet. Sci. 47, 67–90 (2019). A review article that presents the standard explanation of the radius valley by a mass-loss process.
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This is a summary of: Burn, R. et al. A radius valley between migrated steam worlds and evaporated rocky cores. Nat. Astron. https://doi.org/10.1038/s41550-023-02183-7 (2024).
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A model of planetary formation that predicts migrated steam exoplanets and the radius valley. Nat Astron 8, 413–414 (2024). https://doi.org/10.1038/s41550-023-02184-6
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DOI: https://doi.org/10.1038/s41550-023-02184-6
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