Brown Dwarf or Massive Exoplanet? Probing the mysteries of WISE J225540.75-311842.0

Young brown dwarfs are analogs to giant exoplanets, as they share effective temperatures, near-infrared colors and surface gravities. Thus, the detailed spectroscopic characterization of young brown dwarfs may shed light on the study of giant exoplanets, though we are currently unable to observe with sufficient signal-to-noise to allow a precise characterization of their atmospheres. We obtained a high signal-to-noise spectrum of the 2.3 Jupiter-mass brown dwarf WISEPC J225540.75-311842.0 (T8.0) using the J, H, and K bands of the MOSFIRE spectrograph of the Keck I telescope. Here we present our results of the comparison of the spectra of WISEPC J225540.75-311842.0 to different grids atmospheric models for brown dwarfs, as well as to other template late-T dwarfs. We find it highly likely that our object is a young T-dwarf with cloudy atmospheric characteristics that mirror similar substellar bodies HD 3651b and Ross 458c.