TOI-6508 b: A massive transiting brown dwarf orbiting a low-mass star

Bibcode
2025A&A...696A..44B
DOI
10.1051/0004-6361/202453508
Barkaoui, K.; Sebastian, D.; Zúñiga-Fernández, S.; Triaud, A. H. M. J.; Rackham, B. V.; Burgasser, A. J.; Carmichael, T. W.; Gillon, M.; Theissen, C.; Softich, E.; Rojas-Ayala, B.; Srdoc, G.; Soubkiou, A.; Fukui, A.; Timmermans, M.; Stalport, M.; Burdanov, A.; Ciardi, D. R.; Collins, K. A.; Davis, Y. T.; Davoudi, F.; de Wit, J.; Demory, B. O.; Deveny, S.; Dransfield, G.; Ducrot, E.; Florian, L.; Gan, T.; Gómez Maqueo Chew, Y.; Hooton, M. J.; Howell, S. B.; Jenkins, J. M.; Littlefield, C.; Martín, E. L.; Murgas, F.; Niraula, P.; Palle, E.; Pedersen, P. P.; Pozuelos, F. J.; Queloz, D.; Ricker, G.; Schwarz, R. P.; Seager, S.; Shporer, A.; Scott, M. G.; Stockdale, C.; Winn, J.
Bibliographical reference

Astronomy and Astrophysics

Advertised on:
4
2025
Journal
Astronomy and Astrophysics
Number of authors
47
IAC number of authors
5
Citations
8
Refereed citations
4
Description
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 Mp = 72.5‑5.1+7.6 MJup and a radius of Rp = 1.03 ± 0.03 RJup. 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 MBD/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 Teff = 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.
Related projects
Projects' name image
Exoplanets and Astrobiology
The search for life in the universe has been driven by recent discoveries of planets around other stars (known as exoplanets), becoming one of the most active fields in modern astrophysics. The growing number of new exoplanets discovered in recent years and the recent advance on the study of their atmospheres are not only providing new valuable
Enric
Pallé Bago
In progress
Type
Refereed
Exoplanetary Systems & Solar System (SEYSS)

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