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Pelletier S, Benneke B, Ali-Dib M, Prinoth B, Kasper D, Seifahrt A, Bean JL, Debras F, Klein B, Bazinet L, Hoeijmakers HJ, Kesseli AY, Lim O, Carmona A, Pino L, Casasayas-Barris N, Hood T, Stürmer J. Vanadium oxide and a sharp onset of cold-trapping on a giant exoplanet. Nature 2023; 619:491-494. [PMID: 37316661 DOI: 10.1038/s41586-023-06134-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 04/25/2023] [Indexed: 06/16/2023]
Abstract
The abundance of refractory elements in giant planets can provide key insights into their formation histories1. Owing to the low temperatures of the Solar System giants, refractory elements condense below the cloud deck, limiting sensing capabilities to only highly volatile elements2. Recently, ultra-hot giant exoplanets have allowed for some refractory elements to be measured, showing abundances broadly consistent with the solar nebula with titanium probably condensed out of the photosphere3,4. Here we report precise abundance constraints of 14 major refractory elements on the ultra-hot giant planet WASP-76b that show distinct deviations from proto-solar and a sharp onset in condensation temperature. In particular, we find nickel to be enriched, a possible sign of the accretion of the core of a differentiated object during the evolution of the planet. Elements with condensation temperatures below 1,550 K otherwise closely match those of the Sun5 before sharply transitioning to being strongly depleted above 1,550 K, which is well explained by nightside cold-trapping. We further unambiguously detect vanadium oxide on WASP-76b, a molecule long suggested to drive atmospheric thermal inversions6, and also observe a global east-west asymmetry7 in its absorption signals. Overall, our findings indicate that giant planets have a mostly stellar-like refractory elemental content and suggest that temperature sequences of hot Jupiter spectra can show abrupt transitions wherein a mineral species is either present or completely absent if a cold trap exists below its condensation temperature8.
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Affiliation(s)
- Stefan Pelletier
- Department of Physics, Université de Montréal, Montreal, Quebec, Canada.
- Trottier Institute for Research on Exoplanets, Université de Montréal, Montreal, Quebec, Canada.
| | - Björn Benneke
- Department of Physics, Université de Montréal, Montreal, Quebec, Canada
- Trottier Institute for Research on Exoplanets, Université de Montréal, Montreal, Quebec, Canada
| | - Mohamad Ali-Dib
- Center for Astro, Particle, and Planetary Physics, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Bibiana Prinoth
- Lund Observatory, Division of Astrophysics, Department of Physics, Lund University, Lund, Sweden
| | - David Kasper
- Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL, USA
| | - Andreas Seifahrt
- Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL, USA
| | - Jacob L Bean
- Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL, USA
| | | | | | - Luc Bazinet
- Department of Physics, Université de Montréal, Montreal, Quebec, Canada
- Trottier Institute for Research on Exoplanets, Université de Montréal, Montreal, Quebec, Canada
| | - H Jens Hoeijmakers
- Lund Observatory, Division of Astrophysics, Department of Physics, Lund University, Lund, Sweden
| | | | - Olivia Lim
- Department of Physics, Université de Montréal, Montreal, Quebec, Canada
- Trottier Institute for Research on Exoplanets, Université de Montréal, Montreal, Quebec, Canada
| | | | - Lorenzo Pino
- INAF - Osservatorio Astrofisico di Arcetri, Florence, Italy
| | | | - Thea Hood
- Université de Toulouse, CNRS, IRAP, Toulouse, France
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