TOI-333b: A Neptune-desert planet around an F7V star
Observations have shown that planets similar to Neptune are rarely found orbiting Sun-like stars with periods up to ∼4 days. This defines the so-called Neptune desert region. The detection of each individual planet in this region therefore holds a high value by providing detailed insights into the formation and evolution of this population. We report the detection of TOI-333b, a Neptune-desert planet with a mass, radius, and bulk density of 20.1 ± 2.4 M ⊕ , 4.26 ± 0.11 R ⊕ , and 1.42 ± 0.21 g cm −3 . The planet orbits an F7V star every 3.78 d, whose mass, radius, and effective temperature are of 1.2 ± 0.1 M ⊙ , 1.10 ± 0.03 R ⊙ , and 6241 −62 +73 K, respectively. TOI-333bis likely younger than 1 Gyr, which is supported by the doublet Li line around 6707.856 Å and its comparison to Li abundances in open clusters with well-constrained ages. The planet is expected to host only a 8.5 −8.3 +10.9 % gas-to-core mass ratio for an H/He envelope. On the other hand, models of irradiated ocean worlds predict a 20 −10 +11 % H 2 O mass fraction with a core fraction of 35 −23 +20 %. We therefore expect that the internal composition of TOI-333bis dominated by a pure rocky composition with almost no H/He envelope, or a rocky world with almost equal mass fraction of water. Finally, TOI-333bis more massive and larger than 77% and 82% of its Neptune-desert counterparts, and its host ranks among the hottest known stars for Neptune-desert planets. This makes this system a unique laboratory for studying the evolution of these planets around hot stars.
Authors
- Ismael Mireles (ORCID: https://orcid.org/0000-0002-4510-2268)
- Maximiliano Moyano (ORCID: https://orcid.org/0000-0002-7927-9555)
- Christina Hedges (ORCID: https://orcid.org/0000-0002-3385-8391)
- R. David Anderson (ORCID: https://orcid.org/0000-0003-3490-3286)
- M. Lendl (ORCID: https://orcid.org/0000-0001-9699-1459)
- Edward Gillen (ORCID: https://orcid.org/0000-0003-2851-3070)
- M. R. Goad (ORCID: https://orcid.org/0000-0002-2908-7360)
- A. Hughes
- Abderahmane Soubkiou (ORCID: https://orcid.org/0000-0002-0345-2147)
- Alicia Kendall (ORCID: https://orcid.org/0009-0006-0719-9229)
- Arthur Collins
- G. Covone (ORCID: https://orcid.org/0000-0002-2553-096X)
- Christian Magliano (ORCID: https://orcid.org/0000-0001-6343-4744)
- Faith Hawthorn (ORCID: https://orcid.org/0000-0002-8675-182X)
- Robert Burleigh
- Paul Doty
- Suman Saha (ORCID: https://orcid.org/0000-0001-8018-0264)
- James T. Jenkins (ORCID: https://orcid.org/0000-0002-9731-0528)
- Ioannis Apergis (ORCID: https://orcid.org/0009-0004-7473-4573)
- Tafadzwa Zivave (ORCID: https://orcid.org/0009-0001-8055-995X)
- Patrícia Schwarz (ORCID: https://orcid.org/0009-0004-2026-3016)
- Jonathan Wheatley
- J. D. Armstrong
- T.G. Harvey
- Gregor Srdoč
- M. Benjamin Tofflemire
- G. Keivan Stassun
- Troy Edkins
- R.S. Douglas Alves
- P. Matthew Battley
- I. José Vinés
- L. Sarah Casewell
Institutions
- Goddard Space Flight Center (US)
- University of Leicester (GB)
- University of Liège (BE)
- Queen Mary University of London (GB)
- University of New Mexico (US)
- Vanderbilt University (US)
- Observatoire astronomique de Strasbourg (FR)
- Universidad Católica del Norte (CL)
- University of Warwick (GB)
- Astrobiology Center (JP)
- Federico II University Hospital (IT)
- Osservatorio Astrofisico di Catania (IT)
- Center for Astrophysics Harvard & Smithsonian (US)
- Instituto de Estudios Universitarios (MX)
- Réseau Solidarité Itinérance du Québec (CA)
- University of Chile (CL)
- University of Naples Federico II (IT)
- Search for Extraterrestrial Intelligence (US)
- Universidad Diego Portales (CL)
Publication Details
- Journal
- Astronomy and Astrophysics
- Published
- 2025-12-04
- DOI
- https://doi.org/10.1051/0004-6361/202557014
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 0.00