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 \pm 3.3 km s ^ { -1 } 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 M _ { \mathrm { Jup } } .
It is the lowest-mass and nearest isolated member of TW Hydrae at a kinematic distance of 28.9 \pm 3.6 pc , and the second-brightest isolated < 10 M _ { \mathrm { Jup } } object discovered to date .