Deep radiative zones affect giant planet cooling and internal structure: Implications for exoplanet characterisation

[2603.24777] Deep radiative zones affect giant planet cooling and internal structure: Implications for exoplanet characterisation Skip to main content Search Submit Donate Log in Search arXiv Press Enter to search · Advanced search Astrophysics > Earth and Planetary Astrophysics arXiv:2603.24777 (astro-ph) [Submitted on 25 Mar 2026 ( v1 ), last revised 14 Aug 2026 (this version, v2)] Title: Deep radiative zones affect giant planet cooling and internal structure: Implications for exoplanet characterisation Authors: Simon Müller , Ravit Helled View a PDF of the paper titled Deep radiative zones affect giant planet cooling and internal structure: Implications for exoplanet characterisation, by Simon M\"uller and 1 other authors View PDF HTML (experimental) Abstract: The radiative opacity plays a critical role in shaping the thermal evolution and interior structure of giant planets. Near $\sim$ 2,000 K, a hydrogen-transparency region creates a window of reduced opacity that can give rise to detached, deep radiative zones between two convective zones. This local opacity minimum could be deepened further by alkali depletion. While such zones have been explored for Jupiter and Saturn, their influence on cold to warm giant exoplanets remains unstudied. We investigate how opacity windows and the resulting deep radiative zones affect the cooling, radius evolution, and characterisation of giant exoplanet interiors and atmospheres. We computed thermal evolution models for cold to warm Jupiters spanning masses of 0.3 to 4.0 M$_{\rm{J}}$, envelope metallicities from one to ten times solar, equilibrium temperatures of 100 to 800 K, and a parametrised reduction in the radiative opacity. Detached deep radiative zones develop in moderately irradiated Jupiters older than a few gigayears even with unmodified opacities, and earlier and more extensively when the opacity is reduced. The age and equilibrium temperature at which they appear depend on planetary mass, envelope metallicity, and opacity, with metal enrichment suppressing them at low equilibrium temperatures but promoting them at higher ones. A deep opacity window accelerates cooling, reducing predicted radii by up to 5% and interior temperatures by several tens of percent, which translates to a $\sim$ 10 percentage point difference in the inferred bulk metallicity. Deep radiative zones are likely common in warm giant exoplanets and could decouple atmospheric composition from bulk interior composition, complicating the interpretation of atmospheric observations. The opacity treatment therefore introduces significant uncertainties in atmospheric and interior characterisation. Comments: 14 pages, 15 figures, accepted for publication in Astronomy & Astrophysics; significantly revised and extended Subjects: Earth and Planetary Astrophysics (astro-ph.EP) Cite as: arXiv:2603.24777 [astro-ph.EP] (or arXiv:2603.24777v2 [astro-ph.EP] for this version) https://doi.org/10.48550/arXiv.2603.24777 Focus to learn more arXiv-issued DOI via DataCite Submission history From: Simon Müller [ view email ] [v1] Wed, 25 Mar 2026 19:47:29 UTC (568 KB) [v2] Fri, 14 Aug 2026 19:49:15 UTC (3,809 KB) Full-text links: Access Paper: View a PDF of the paper titled Deep radiative zones affect giant planet cooling and internal structure: Implications for exoplanet characterisation, by Simon M\"uller and 1 other authors View PDF HTML (experimental) TeX Source view license Current browse context: astro-ph.EP < prev | next > new | recent | 2026-03 Change to browse by: astro-ph References & Citations NASA ADS Google Scholar Semantic Scholar export BibTeX citation Loading... BibTeX formatted citation × loading... Data provided by: Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer ( What is the Explorer? ) Connected Papers Toggle Connected Papers ( What is Connected Papers? ) Litmaps Toggle Litmaps ( What is Litmaps? ) scite.ai Toggle scite Smart Citations ( What are Smart Citations? ) Code, Data, Media Code, Data and Media Associated with this Article alphaXiv Toggle alphaXiv ( What is alphaXiv? ) Links to Code Toggle CatalyzeX Code Finder for Papers ( What is CatalyzeX? ) DagsHub Toggle DagsHub ( What is DagsHub? ) GotitPub Toggle Gotit.pub ( What is GotitPub? ) Huggingface Toggle Hugging Face ( What is Huggingface? ) ScienceCast Toggle ScienceCast ( What is ScienceCast? ) Demos Demos Replicate Toggle Replicate ( What is Replicate? ) Spaces Toggle Hugging Face Spaces ( What is Spaces? ) Spaces Toggle TXYZ.AI ( What is TXYZ.AI? ) Related Papers Recommenders and Search Tools Link to Influence Flower Influence Flower ( What are Influence Flowers? ) Core recommender toggle CORE Recommender ( What is CORE? ) IArxiv recommender toggle IArxiv Recommender ( What is IArxiv? ) Author Venue Institution Topic About arXivLabs arXivLabs: experimental projects with community collaborators arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website. Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them. Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs . Which authors of this paper are endorsers? | Disable MathJax ( What is MathJax? ) We gratefully acknowledge support from our major funders , member institutions , , and all contributors. About · Help · Contact · Subscribe · Copyright · Privacy · Accessibility · Operational Status (opens in new tab) Major funding support from

Related documents

• Habitability and exchange processes on the Jovian moons: implications for planetary protection measures#1090378
• Super-Earth Interiors Shrink by About 10% as They Crystallise#1048840
• Ice Giants Revisited: Uranus and Neptune as Magma Ocean Worlds#971825
• Improved Constraints on the Surface of LHS 3844 b from its Mid-Infrared Spectrum#1142284
• Individual Variability in the Peripheral and Core Interthreshold Zones#70000