Two Intermediate-mass Transiting Brown Dwarfs from the TESS Mission

Carmichael, Theron W.; Quinn, Samuel N.; Mustill, Alexander J.; Huang, Chelsea; Zhou, George; Persson, Carina M.; Nielsen, Louise D.; Collins, Karen A.; Ziegler, Carl; Collins, Kevin I.; Rodriguez, Joseph E.; Shporer, Avi; Brahm, Rafael; Mann, Andrew W.; Bouchy, Francois; Fridlund, Malcolm; Stassun, Keivan G.; Hellier, Coel; Seidel, Julia V.; Stalport, Manu; Udry, Stephane; Pepe, Francesco; Ireland, Michael; Žerjal, Maruša; Briceño, César; Law, Nicholas; Jordán, Andrés; Espinoza, Néstor; Henning, Thomas; Sarkis, Paula; Latham, David W.

Abstract

We report the discovery of two intermediate-mass transiting brown dwarfs (BDs), TOI-569b and TOI-1406b, from NASA's Transiting Exoplanet Survey Satellite mission. TOI-569b has an orbital period of P = 6.55604 ± 0.00016 days, a mass of Mb = 64.1 ± 1.9 ${M}_{{\rm{J}}}$, and a radius of Rb = 0.75 ± 0.02 ${R}_{{\rm{J}}}$. Its host star, TOI-569, has a mass of M⋆ = 1.21 ± 0.05 $\,{M}_{\odot }$, a radius of R⋆ = 1.47 ± 0.03 $\,{R}_{\odot }$, $[\mathrm{Fe}/{\rm{H}}]=+0.29\pm 0.09$ dex, and an effective temperature of Teff = 5768 ± 110 K. TOI-1406b has an orbital period of P = 10.57415 ± 0.00063 days, a mass of Mb = 46.0 ± 2.7 ${M}_{{\rm{J}}}$, and a radius of Rb = 0.86 ± 0.03 ${R}_{{\rm{J}}}$. The host star for this BD has a mass of M⋆ = 1.18 ± 0.09 $\,{M}_{\odot }$, a radius of R⋆ = 1.35 ± 0.03 $\,{R}_{\odot }$, $[\mathrm{Fe}/{\rm{H}}]=-0.08\pm 0.09$ dex, and an effective temperature of Teff = 6290 ± 100 K. Both BDs are in circular orbits around their host stars and are older than 3 Gyr based on stellar isochrone models of the stars. TOI-569 is one of two slightly evolved stars known to host a transiting BD (the other being KOI-415). TOI-1406b is one of three known transiting BDs to occupy the mass range of 40–50 ${M}_{{\rm{J}}}$ and one of two to have a circular orbit at a period near 10 days (with the first being KOI-205b). Both BDs have reliable ages from stellar isochrones, in addition to their well-constrained masses and radii, making them particularly valuable as tests for substellar isochrones in the BD mass–radius diagram.

Citation

Carmichael, T. W., Quinn, S. N., Mustill, A. J., Huang, C., Zhou, G., Persson, C. M., …Latham, D. W. (in press). Two Intermediate-mass Transiting Brown Dwarfs from the TESS Mission. Astronomical Journal, 160(1), 53. https://doi.org/10.3847/1538-3881/ab9b84

• Journal Article Type: Article
• Acceptance Date: Jun 9, 2020
• Online Publication Date: Jul 2, 2020
• Deposit Date: Jun 16, 2023
• Journal: The Astronomical Journal
• Print ISSN: 0004-6256
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 160
• Issue: 1
• Pages: 53
• DOI: https://doi.org/10.3847/1538-3881/ab9b84
• Keywords: Space and Planetary Science; Astronomy and Astrophysics
• Additional Information: Journal title: The Astronomical Journal; Article type: paper; Article title: Two Intermediate-mass Transiting Brown Dwarfs from the TESS Mission; Copyright information: © 2020. The American Astronomical Society. All rights reserved.; Date received: 2020-02-04; Date accepted: 2020-06-09; Online publication date: 2020-07-02