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arXiv · 1405.0511

WISEP J061135.13-041024.0AB: A J-Band Flux Reversal Binary at the L/T Transition

Christopher R. Gelino·R. L. Smart·Federico Marocco·J. Davy Kirkpatrick·Michael C. Cushing·Gregory Mace·Rene A. Mendez·C. G. Tinney·Hugh R. A. Jones
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Abstract

We present Keck II laser guide star adaptive optics observations of the brown dwarf WISEP J061135.13-041024.0 showing it is a binary with a component separation of 0.4". This system is one of the six known resolved binaries in which the magnitude differences between the components show a reversal in sign between the Y/J band and the H/K bands. Deconvolution of the composite spectrum results in a best fit binary solution with L9 and T1.5 components. We also present a preliminary parallax placing the system at a distance of 21.2+/-1.3 pc. Using the distance and resolved magnitudes we are able to place WISEP J061135.13-041024.0AB on a color-absolute magnitude diagram, showing that this system contributes to the well-known "J-band bump" and the components' properties appear similar to other late-type L and early-type T dwarfs. Fitting our data to a set of cloudy atmosphere models suggests the system has an age >1 Gyr with WISEP J061135.13-041024.0A having an effective temperature (Teff) of 1275-1325 K and mass of 64-65 M_Jup, and WISEP J061135.13-041024.0B having Teff = 1075-1115 K and mass 40-65 M_Jup.

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Christopher R. Gelino, R. L. Smart, Federico Marocco, J. Davy Kirkpatrick, Michael C. Cushing, Gregory Mace, Rene A. Mendez, C. G. Tinney, Hugh R. A. Jones. 2014-05-02. WISEP J061135.13-041024.0AB: A J-Band Flux Reversal Binary at the L/T Transition. https://arxiv.org/abs/1405.0511

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