Eleven New Transiting Brown Dwarfs and Very-low-mass Stars from TESS

Vowell, Noah; Rodriguez, Joseph E.; Latham, David W.; Quinn, Samuel N.; Schulte, Jack; Eastman, Jason D.; Bieryla, Allyson; Barkaoui, Khalid; Ciardi, David R.; Collins, Karen A.; Girardin, Eric; Hébrard, Guillaume; Heldridge, Elisabeth; Jafariyazani, Marziye; Kotten, Brooke; Mancini, Luigi; Murgas, Felipe; Narita, Norio; Radford, D. J.; Relles, Howard M.; Shporer, Avi; Soares-Furtado, Melinda; Strakhov, Ivan A.; Ziegler, Carl; Boisse, Isabelle; Briceño, César; Calkins, Michael L.; Clark, Catherine A.; Collins, Kevin I.; de Leon, Jerome; Esquerdo, Gilbert A.; Fajardo-Acosta, Sergio B.; Forveille, Thierry; Fukui, Akihiko; Watkins, Cristilyn N.; He, Ruixuan; Heidari, Neda; Horne, Keith; Jenkins, Jon M.; Mann, Andrew W.; Naponiello, Luca; Palle, Enric; Schwarz, Richard P.; Seager, S.; Southworth, John; Srdoc, Gregor; Swift, Jonathan J.; Winn, Joshua N.

Abstract

We present the discovery of 11 new transiting brown dwarfs (BDs) and low-mass M dwarfs from NASA’s Transiting Exoplanet Survey Satellite (TESS) mission: TOI-2844, TOI-3122, TOI-3577, TOI-3755, TOI-4462, TOI-4635, TOI-4737, TOI-4759, TOI-5240, TOI-5467, and TOI-5882. They consist of five BD companions and six very-low-mass stellar companions ranging in mass from 25 MJ to 128 MJ. We used a combination of photometric time-series, spectroscopic, and high-resolution imaging follow-up as a part of the TESS Follow-up Observing Program (or TFOP) to characterize each system. With over 50 transiting BDs confirmed, we now have a large enough sample to directly test different formation and evolutionary scenarios. We provide a renewed perspective on the transiting “brown dwarf desert” and its role in differentiating between planetary and stellar formation mechanisms. Our analysis of the eccentricity distribution for the transiting BD sample does not support previous claims of a transition between planetary and stellar formation at ∼42 MJ. We also contribute a first look into the metallicity distribution of transiting companions in the range 7–150 MJ, showing that this does not support a ∼42 MJ transition too. Finally, we also detect a significant lithium absorption feature in one of the BD hosts (TOI-5882). However, we determine that the host star is likely old based on rotation, kinematic, and photometric mdeasurements. We therefore claim that TOI-5882 may be a candidate for planetary engulfment.

Citation

Vowell, N., Rodriguez, J. E., Latham, D. W., Quinn, S. N., Schulte, J., Eastman, J. D., Bieryla, A., Barkaoui, K., Ciardi, D. R., Collins, K. A., Girardin, E., Hébrard, G., Heldridge, E., Jafariyazani, M., Kotten, B., Mancini, L., Murgas, F., Narita, N., Radford, D. J., Relles, H. M., …Winn, J. N. (2025). Eleven New Transiting Brown Dwarfs and Very-low-mass Stars from TESS. Astronomical Journal, 170(2), Article 68. https://doi.org/10.3847/1538-3881/addd17

• Journal Article Type: Article
• Acceptance Date: May 19, 2025
• Online Publication Date: Jul 4, 2025
• Publication Date: Aug 4, 2025
• Deposit Date: Jul 14, 2025
• Publicly Available Date: Jul 14, 2025
• Journal: The Astronomical Journal
• Print ISSN: 0004-6256
• Electronic ISSN: 1538-3881
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 170
• Issue: 2
• Article Number: 68
• DOI: https://doi.org/10.3847/1538-3881/addd17
• Keywords: Radial velocity, M dwarf stars, Brown dwarfs, Exoplanets, Transits
• Public URL: https://keele-repository.worktribe.com/output/1322101
• Publisher URL: https://iopscience.iop.org/article/10.3847/1538-3881/addd17