We report the confirmation of the binary nature of the nearby , very low-mass system NLTT 33370 with adaptive optics imaging and present resolved near-infrared photometry and integrated light optical and near-infrared spectroscopy to characterize the system .
VLT-NaCo and LBTI-LMIRCam images show significant orbital motion between 2013 February and 2013 April .
Optical spectra reveal weak , gravity sensitive alkali lines and strong lithium 6708 Å absorption that indicate the system is younger than field age .
VLT-SINFONI near-IR spectra also show weak , gravity sensitive features and spectral morphology that is consistent with other young , very low-mass dwarfs .
We combine the constraints from all age diagnostics to estimate a system age of \sim 30-200 Myr .
The 1.2-4.7 \mu m spectral energy distribution of the components point toward \mathrm { T _ { eff } = 3200 \pm 500 } K and \mathrm { T _ { eff } = 3100 \pm 500 } K for NLTT 33370 A and B , respectively .
The observed spectra , derived temperatures , and estimated age combine to constrain the component spectral types to the range M6-M8 .
Evolutionary models predict masses of 113 \pm 8 M _ { Jup } and 106 \pm 7 M _ { Jup } from the estimated luminosities of the components .
KPNO-Phoenix spectra allow us to estimate the systemic radial velocity of the binary .
The Galactic kinematics of NLTT 33370AB are broadly consistent with other young stars in the Solar neighborhood .
However , definitive membership in a young , kinematic group can not be assigned at this time and further follow-up observations are necessary to fully constrain the system ’ s kinematics .
The proximity , age , and late-spectral type of this binary make it very novel and an ideal target for rapid , complete orbit determination .
The system is one of only a few model calibration benchmarks at young ages and very low-masses .