TOI-3862 b: A dense super-Neptune deep in the hot Neptune desert
Context. The structure and evolution of close-in exoplanets are shaped by atmospheric loss and migration processes, which give rise to key population features such as the hot Neptune desert, ridge, and savanna – regions of the period-radius space whose boundaries offer critical insights into planetary formation and survival. Aims. As part of the KESPRINT collaboration, we selected the TESS transiting planet candidate TOI-3862.01 for radial velocity follow-up to confirm its planetary nature and characterize its mass and bulk properties. This planet candidate is of particular interest due to its position in the middle of the hot Neptune desert, making it a valuable probe for testing theories of planet migration and atmospheric loss. Methods. We confirmed the planetary nature and determined the mass of TOI-3862.01 (hereinafter TOI-3862 b) by performing a joint fit with both transit and radial velocity data, precisely characterizing the bulk properties of this planet. Results. TOI-3862b is a super-Neptune on a 1.56-day orbit around a Sun-like star with an effective temperature of 5300±50 K. It has a mass of 53.7−2.9+2.8 M⊕ and a radius of 5.53 ± 0.18 R⊕, corresponding to a density of 1.7±0.2 g/cm3. This places it among the rare population of hot and dense super-Neptune desert planets. Conclusions. TOI-3862b, residing deep in the hot Neptune desert, represents a rare occurrence in an otherwise sparsely populated region, offering a valuable opportunity to probe the processes that may allow planets to survive in such environments.
Authors
- Pau Bosch-Cabot (ORCID: https://orcid.org/0000-0002-1514-5558)
- E. Knudstrup
- E. J. Michaels
- Steve B. Howell (ORCID: https://orcid.org/0000-0002-2532-2853)
- G. Lacedelli (ORCID: https://orcid.org/0000-0002-4197-7374)
- A. Castro-González (ORCID: https://orcid.org/0000-0001-7439-3618)
- Richard P. Schwarz (ORCID: https://orcid.org/0000-0001-8227-1020)
- C. M. Persson
- John H. Livingston (ORCID: https://orcid.org/0000-0002-4881-3620)
- Eduardo Lorenzo Martín Guerrero de Escalante
- Monika Rogowska Stangret
- José I Vines (ORCID: https://orcid.org/0000-0002-1896-2377)
- Núria Casasayas Barris
- Keivan G. Stassun (ORCID: https://orcid.org/0000-0002-3481-9052)
- Bob Massey
- Furlan Elise
- Pere Guerra
- Felipe Mergas
- Cristilyn N. Watkins (ORCID: https://orcid.org/0000-0002-9733-161X)
- S. González (ORCID: https://orcid.org/0000-0001-9926-998X)
- Stavros Chairetas
- Hannu Parvianien
- Kai Ikuta
- Ilaria Carleo
- Judith Korth
- Rafael Delfin Barrena Delgado
- Noriharu Watanabe
- Izuru Fukuda
- Andrew Boyle
- Sergio Messina
- Avi Shporer
- Jaume Orell-Miquel
- Enric Palle
- Patrick Eggenberger
- Vincent Bourrier
- Davide Gandolfi
- Giuseppe Morello
- Coel Hellier
- Seth Redfield
- Akihiko Fukui
- Boris Safonov
- Jorge Lillo-Box
- David Baker
- Kiyoe Kawauchi
- Dawid Jankowski
- William Cochran
- Thomas Masseron
- Florence Libotte
- Norio Narita
- Grzegorz Nowak
- Krzysztof Goździewski
- Allyson Bieryla
- E. W. Wong
- M. B. Lund
- H. J. Deeg
Publication Details
- Journal
- Springer Link (Chiba Institute of Technology)
- Published
- 2026-02-27
- DOI
- https://doi.org/10.1051/0004-6361/202557186/pdf
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- National Aeronautics and Space Administration
- W. M. Keck Foundation
- Gordon and Betty Moore Foundation
- California Institute of Technology
- Space Telescope Science Institute
- European Commission
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Swedish National Space Agency
- Ministry of Science, ICT and Future Planning
- Korea Astronomy and Space Science Institute
- Ministerio de Ciencia e Innovación
- Uniwersytet Mikolaja Kopernika w Toruniu
- Ministério da Ciência, Tecnologia, Inovações e Comunicações
- Agencia Nacional de Investigación y Desarrollo
- Ames Research Center
- Jet Propulsion Laboratory
- Science Mission Directorate
- Japan Society for the Promotion of Science
- European Regional Development Fund
- Agencia Estatal de Investigación