TOI-6508 b: A massive transiting brown dwarf orbiting a low-mass star
We report the discovery of a transiting brown dwarf orbiting a low-mass star, TOI-6508 b. Today, only ∼50 transiting brown dwarfs have been discovered. TOI-6508 b was first detected with data from the Transiting Exoplanet Survey Satellite ( TESS ) in Sectors 10, 37 and 63. Ground-based follow-up photometric data were collected with the SPECULOOS-South (Search for habitable Planets EClipsing ULtra-cOOl Stars) and LCOGT-1m telescopes, and RV measurements were obtained with the Near InfraRed Planet Searcher (NIRPS) spectrograph. We find that TOI-6508 b has a mass of M p = 72.5 −5.1 +7.6 M Jup and a radius of R p = 1.03 ± 0.03 R Jup . Our modeling shows that the data are consistent with an eccentric orbit of 19 day and an eccentricity of e = 0.28 −0.08 +0.09 . TOI-6508 b has a mass ratio of M BD / M ★ = 0.40, makes it the second highest mass ratio brown dwarf that transits a low-mass star. The host has a mass of M ★ = 0.174 ± 0.004 M ⊙ , a radius of R ★ = 0.205 ± 0.006 R ⊙ , an effective temperature of T eff = 2930 ± 70 K, and a metallicity of [ Fe/H ] = −0.22 ± 0.08. This makes TOI-6508 b an interesting discovery that has come to light in a region still sparsely populated.
Authors
- E. Palle
- Benjamin V. Rackham (ORCID: https://orcid.org/0000-0002-3627-1676)
- B. -O. Demory
- A. Shporer
- C. Stockdale
- F. Murgas
- D.R. Ciardi
- E. L. Martín (ORCID: https://orcid.org/0000-0002-5008-1596)
- M. Gillon (ORCID: https://orcid.org/0000-0003-1462-7739)
- A. Burdanov
- Daniel Sebastian (ORCID: https://orcid.org/0000-0002-2214-9258)
- F. J. Pozuelos (ORCID: https://orcid.org/0000-0003-1572-7707)
- K.A. Collins
- T.W. Carmichael
- K. Barkaoui
- D. Queloz
- J.M. Jenkins
- J. de Wit
- Adam J. Burgasser (ORCID: https://orcid.org/0000-0002-6523-9536)
- S. Seager
- Sebastián Zúñiga-Fernández (ORCID: https://orcid.org/0000-0002-9350-830X)
- G. Ricker
- Yasmin Davis (ORCID: https://orcid.org/0009-0000-6625-137X)
- A. H. M. J. Triaud (ORCID: https://orcid.org/0000-0002-5510-8751)
- Y. Gómez Maqueo Chew (ORCID: https://orcid.org/0000-0002-7486-6726)
- S. B. Howell
- M. J. Hooton
- Fatemeh Davoudi (ORCID: https://orcid.org/0000-0002-1787-3444)
- R.P. Schwarz
- Colin Littlefield (ORCID: https://orcid.org/0000-0001-7746-5795)
- Prajwal Niraula (ORCID: https://orcid.org/0000-0002-8052-3893)
- Christopher A. Theissen (ORCID: https://orcid.org/0000-0002-9807-5435)
- G. Srdoc
- M. Timmermans
- B. Rojas-Ayala
- Tianjun Gan (ORCID: https://orcid.org/0000-0002-4503-9705)
- A. Soubkiou
- Emma Softich (ORCID: https://orcid.org/0000-0002-1420-1837)
- G. Dransfield
- Elsa Ducrot (ORCID: https://orcid.org/0000-0002-7008-6888)
- A. Fukui
- M. Stalport
- Sarah J. Deveny (ORCID: https://orcid.org/0009-0002-9833-0667)
- P.P. Pedersen
- Joshua N. Winn (ORCID: https://orcid.org/0000-0002-4265-047X)
- M. G. Scott (ORCID: https://orcid.org/0009-0006-3846-4558)
- L. Florian
Institutions
- University of Bern (CH)
- Cadi Ayyad University (MA)
- California Institute of Technology (US)
- Ames Research Center (US)
- Centre National de la Recherche Scientifique (FR)
- Planetary Science Institute (US)
- University of Hawaii System (US)
- University of Liège (BE)
- Universidad de La Laguna (ES)
- Universidad Autónoma de la Ciudad de México (MX)
- University of Tarapacá (CL)
- Princeton University (US)
- Université Paris Cité (FR)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- Université Paris-Saclay (FR)
- NASA Exoplanet Science Institute (US)
- ETH Zurich (CH)
- University of California San Diego (US)
- Astrophysique, Instrumentation et Modélisation (FR)
- Cavendish Hospital (GB)
- Bay Area Environmental Research Institute (US)
- Center for Astrophysics Harvard & Smithsonian (US)
- CEA Paris-Saclay (FR)
- Instituto de Astrofísica de Canarias (ES)
- Tokyo Metropolitan Komaba High School (JP)
- Instituto de Astrofísica de Andalucía (ES)
- Ellinbank Observatory (AU)
- American Institute of Aeronautics and Astronautics (US)
- Massachusetts Institute of Technology (US)
- Université de Montréal (CA)
- The University of Tokyo (JP)
- University of Birmingham (GB)
- Universidad Nacional Autónoma de México (MX)
- Tsinghua University (CN)
Publication Details
- Journal
- Astronomy and Astrophysics
- Published
- 2025-03-17
- DOI
- https://doi.org/10.1051/0004-6361/202453508
- Citations
- 8
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 9.24
Funders
- National Science Foundation
- National Aeronautics and Space Administration
- California Institute of Technology
- Space Telescope Science Institute
- European Commission
- Fonds De La Recherche Scientifique - FNRS
- Fédération Wallonie-Bruxelles
- Ministry of Science, ICT and Future Planning
- Nuclear Safety and Security Commission
- Korea Astronomy and Space Science Institute
- European Southern Observatory
- Ministerio de Ciencia e Innovación
- Ministério da Ciência, Tecnologia, Inovações e Comunicações
- Agencia Nacional de Investigación y Desarrollo
- Ames Research Center
- Science Mission Directorate
- Science and Technology Facilities Council
- Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture
- Agencia Estatal de Investigación