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arXiv · 1603.08529

The Nearest Isolated Member of the TW Hydrae Association is a Giant Planet Analog

Kendra Kellogg·Stanimir Metchev·Jonathan Gagne·Jacqueline Faherty
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Abstract

In a recent search for unusually red L and T dwarfs, we identified 2MASS J11193254-1137466 as a likely young L7 dwarf and potential member of the TW Hydrae association. We present spectra that confirm the youth of this object. We also measure a radial velocity of 8.5 +/- 3.3 km/s that, together with the sky position, proper motion and photometric distance, results in a 92% probability of membership in the TW Hydrae association, with a calibrated field contamination probability of 0.0005% using the BANYAN II tool. Using the age of TW Hydrae and the luminosity of 2MASS J11193254-1137466, we estimate its mass to be 4.3--7.6 MJup. It is the lowest-mass and nearest isolated member of TW Hydrae at a kinematic distance of 28.9 +/- 3.6 pc, and the second-brightest isolated <10 MJup object discovered to date.

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Kendra Kellogg, Stanimir Metchev, Jonathan Gagne, Jacqueline Faherty. 2016-03-28. The Nearest Isolated Member of the TW Hydrae Association is a Giant Planet Analog. https://doi.org/10.3847/2041-8205%2F821%2F1%2Fl15

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