TOI-3862 b: A dense super-Neptune deep in the hot Neptune desert
Year: 2026
Type: article
Abstract: 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/cm 3 . 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.
Source: Astronomy and Astrophysics
Authors: Ilaria Carleo, Amadeo Castro-González, Enric Pallé, Felipe Murgas, Grzegorz Nowak, Gaia Lacedelli, Thomas Masseron, Emily W. Wong, Patrick Eggenberger, Vincent Bourrier, Dawid Jankowski, Krzysztof Goździewski, Douglas R. Alves, James S. Jenkins, Sergio Messina, Keivan G. Stassun, Jose I. Vines, Matteo Brogi, David R. Ciardi, Catherine A. Clark, William Cochran, Karen A. Collins, Hans J. Deeg, Elise Furlan, Davide Gandolfi, Samuel Geraldía González, Artie P. Hatzes, Coel Hellier, Steve B. Howell, Judith Korth, Jorge Lillo-Box, John H. Livingston, Jaume Orell-Miquel, Carina M. Persson, Seth Redfield, Boris Safonov, David Baker, Rafael Delfin Barrena Delgado, Allyson Bieryla, Andrew Boyle, Pau Bosch-Cabot, Núria Casasayas Barris, Stavros Chairetas, Jerome P. de Leon, Izuru Fukuda, Akihiko Fukui, Pere Guerra, Kai Ikuta, Kiyoe Kawauchi, Emil Knudstrup, Florence Libotte, Michael B. Lund, Rafael Luque, Eduardo Lorenzo Martín Guerrero de Escalante, Bob Massey, Edward J. Michaels, Giuseppe Morello, Norio Narita, Hannu Parvianien, Richard P. Schwarz, Avi Shporer, Monika Stangret, Noriharu Watanabe, Cristilyn N. Watkins
Institutions: Osservatorio Astrofisico di Torino, Instituto de Astrofísica de Canarias, National Institute for Astrophysics, University of Geneva, Universidad de La Laguna, Nicolaus Copernicus University, Centro de Astrofísica y Tecnologías Afines, University of Chile, Universidad Diego Portales, Osservatorio Astrofisico di Catania, Vanderbilt University, University of Turin, California Institute of Technology, NASA Exoplanet Science Institute, Infrared Processing and Analysis Center, The University of Texas at Austin, Center for Astrophysics Harvard & Smithsonian, Keele University, Ames Research Center, Centro de Astrobiología, The Graduate University for Advanced Studies, SOKENDAI, Astrobiology Center, National Astronomical Observatory of Japan, Chalmers University of Technology, Wesleyan University, Lomonosov Moscow State University, Austin College, University of North Carolina at Chapel Hill, The University of Tokyo, Hitotsubashi University, Ritsumeikan University, Aarhus University, Royal Belgian Institute for Space Aeronomy, Consejo Superior de Investigaciones Científicas, Instituto de Astrofísica de Andalucía, Smithsonian Institution, Osservatorio Astronomico di Palermo, Massachusetts Institute of Technology
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
OpenAlex ID: W7124285856