WISEA J114724.10-204021.3: A Free-Floating Planetary Mass Member of the TW Hya Association

WISEA J114724.10-204021.3: A Free-Floating Planetary Mass Member of the TW Hya Association

Authors:

Schneider et al

Abstract:

We present WISEA J114724.10−204021.3, a young, low-mass, high probability member of the TW Hya association. WISEA J114724.10−204021.3 was discovered based on its red AllWISE color (W1−W2 = 0.63 mag) and extremely red 2MASS J−KS color (greater than 2.64 mag), the latter of which is confirmed with near-infrared photometry from the VISTA Hemisphere Survey (J−KS = 2.57±0.03). Follow-up near-infrared spectroscopy shows a spectral type of L7 ± 1 as well as several spectroscopic indicators of youth. These include a peaked H-band shape and a steeper K-band slope, traits typically attributed to low surface gravity. The sky position, proper motion, and distance estimates of WISEA J114724.10−204021.3 are all consistent with membership in the ∼10 Myr old TW Hya association. Using the age of the TW Hya association and evolutionary models, we estimate the mass of WISEA J114724.10−204021.3 to be 5−13 MJup, making it one of the youngest and lowest mass free-floating objects yet discovered in the Solar neighborhood.