SDSS J111010.01+011613.1: A New Planetary-mass T Dwarf Member of the AB Doradus Moving Group

Author(s): Jonathan Gagne, Adam J. Burgasser, Jacqueline K. Faherty, David Lafreniere, Rene Doyon, Christine Nicholls
Abstract: We present a new radial velocity measurement that, together with a trigonometric parallax, proper motion and signs of low gravity from the literature, confirms that SDSS J111010.01+011613.1 is a new T5.5 bona fide member of AB Doradus. Fitting λ/Δλ ≈ 6000 Folded-port InfraRed Echellette spectroscopy in the 1.20-1.33 μm region to BT-Settl atmosphere models yielded a radial velocity of 7.5 ± 3.8 km s^-1. At such a young age (110-130 Myr), current evolution models predict a mass of ~ 10-12 M_Jup, thus placing SDSS J1110+0116 well into the planetary-mass regime. We compare the fundamental properties of SDSS J1110+0116 with a sequence of seven recently identified M8-T5 brown dwarf bona fide or high-confidence candidate members of AB Doradus. We also note that its near-infrared J-K color is redder than field T5-T6 brown dwarfs, however its absolute J-band magnitude is similar to them. SDSS J1110+0116 is one of the few age-calibrated T dwarfs known to date, as well as one of the coolest bona fide members of a young moving group.
Organisation(s): Department of Astrophysics
External organisation(s): University of Montreal, University of California, San Diego, Carnegie Institution for Science, American Museum of Natural History
Journal: The Astrophysical journal Letters
Volume: 808
No. of pages: 6
ISSN: 2041-8205
DOI: https://doi.org/10.1088/2041-8205/808/1/L20
Publication date: 07-2015
Peer reviewed: Yes
Austrian Fields of Science 2012: 103003 Astronomy, 103004 Astrophysics
ASJC Scopus subject areas: Astronomy and Astrophysics, Space and Planetary Science
Portal url: https://ucrisportal.univie.ac.at/en/publications/sdss-j111010010116131-a-new-planetarymass-t-dwarf-member-of-the-ab-doradus-moving-group(df69a59b-ca02-4a50-8d04-81460192da1e).html

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