{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/volatile-rich-evolution-of-molten-super-earth","title":"Volatile-rich evolution of molten super-Earth L 98-59 d","arxiv_id":"2507.02656","date":"2025-07-03","proceeding":null,"authors":["Harrison Nicholls","Tim Lichtenberg","Richard D. Chatterjee","Claire Marie Guimond","Emma Postolec","Raymond T. Pierrehumbert"],"abstract":"Small low-density exoplanets are sculpted by strong stellar irradiation, but their primordial compositions and subsequent evolution are still unknown. Two often-considered scenarios hold that they formed with rocky interiors and H$_2$-He atmospheres ('gas-dwarfs'), or alternatively with bulk compositions dominated by H$_2$O phases ('water-worlds'). Here, we constrain the possible range of evolutionary histories linking the birth conditions of low-density super-Earth L 98-59 d to recent observations using a coupled atmosphere-interior evolutionary model. We find that the observations can be explained by in-situ photochemical production of SO$_2$ in an H$_2$ background, indicative of a chemically-reducing mantle and substantial (1.8 mass pct.) early sulfur and hydrogen content, inconsistent with both the gas-dwarf and water-world scenarios. L 98-59 d's interior comprises a permanent magma ocean, allowing long-term retention of volatiles within its mantle over billions of years, consistent with California-Kepler Survey trends. Our analysis reveals an evolutionary pathway in which planets host volatile-rich atmospheres sustained by long-term magma ocean degassing, shaped by secular cooling, atmospheric erosion and photochemistry. Internal and environmental processes contribute to the observed diversity of super-Earth and sub-Neptune exoplanets.","url_abs":"https://arxiv.org/abs/2507.02656v1","url_pdf":"https://arxiv.org/pdf/2507.02656v1.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"volatile-rich-evolution-of-molten-super-earth","repo_url":"https://github.com/nichollsh/AGNI","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":1,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}