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arXiv · 1506.04195

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

Jonathan Gagné·Adam J. Burgasser·Jacqueline K. Faherty·David Lafrenière·René Doyon·Joseph C. Filippazzo·Emily Bowsher·Christine P. Nicholls
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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 $λ/Δλ$ $\approx$ 6000 FIRE spectroscopy in the 1.20-1.33 $μ$m region to BT-Settl atmosphere models yielded a radial velocity of $7.5 \pm 3.8$ km s$^{-1}$. At such a young age (110-130 Myr), current evolution models predict a mass of $\sim$ 10-12 $M_{\mathrm{Jup}}$, 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.

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Jonathan Gagné, Adam J. Burgasser, Jacqueline K. Faherty, David Lafrenière, René Doyon, Joseph C. Filippazzo, Emily Bowsher, Christine P. Nicholls. 2015-06-12. SDSS J111010.01+011613.1: A New Planetary-Mass T Dwarf Member of the AB Doradus Moving Group. https://doi.org/10.1088/2041-8205%2F808%2F1%2Fl20

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