Discovery of a 0.15" Binary Brown Dwarf 2MASSJ 1426316+155701 With Gemini/Hokupa'a Adaptive Optics

Abstract

Use of the highly sensitive Hokupa'a curvature wavefront sensor has allowed for the first time direct adaptive optics (AO) guiding on brown dwarfs and VLM stars (SpT=M7-L2). An initial survey of 9 such objects discovered one 0.15" binary (2MASSJ 1426316+155701). The companion is about half as bright as the primary (Delta K = 0.61+/-0.05$,DeltaH=0.70+/-0.05)andhasevenreddercolorsH-K=0.59+/-0.14thantheprimary.TheblendedspectrumofthebinaryhasbeenpreviouslydeterminedtobeM\mathrm{9.0.}WemodeledablendofanM8.5templateandaL1-L3templatereproducingaM9.0spectruminthecaseofDeltaK=0.61+/-0.05,DeltaH=0.70\pm 0.05$. These spectral types also match the observed H-K colors of each star. Based the previously observed low space motion and $H_{\alpha }$ activity we assign an age of $0.8_{-0.3}^{+6.7}Gyr$. Utilizing this age range and the latest DUSTY models of the Lyon group we assign a photometric distance of $18.8_{-1.02}^{+1.44}pc$ and masses of $M_A=0.074_{-0.011}^{+0.005}{M}_{\odot }$ and $M_B=0.066_{-0.015}^{+0.006}{M}_{\odot }$. We therefore estimate a system separation of $2.92_{+0.22}^{-0.16}AU$ and a period of $13.3{+3.18}^{-1.51}yr$ respectively. Hence, 2M1426 is among the smallest separation brown dwarf binaries resolved to date.

References in corpus (11)

• New Neighbors from 2MASS: Activity and Kinematics at the Bottom of the Main Sequence
• Infrared Spectra and Spectral Energy Distributions of Late-M- and L-Dwarfs
• On the Radii of Close-in Giant Planets
• A search for L dwarf binary systems
• Near-Infrared Spectral Classification of late-M and L Dwarfs
• Membership and Multiplicity among Very Low-Mass Stars and Brown Dwarfs in the Pleiades Cluster
• PPl 15: The First Brown Dwarf Spectroscopic Binary
• The orbit of the brown dwarf binary Gl 569B
• Keck Imaging of Binary L Dwarfs
• The Discovery of a Companion to the Very Cool Dwarf Gl~569~B with the Keck Adaptive Optics Facility
• Gliese 569B: A young multiple brown dwarf system?

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