We report seven successful observations of the astrometric binary GJ 164 AB system with aperture masking interferometry. The companion, with a near infrared contrast of 5:1 was detected beyond the formal diffraction limit. Combined with astrometric observations from the literature, these observations fix the parallax of the system, and allow a model-independent mass determination of both components. We find the mass of GJ 164B to be 0.086±0.007M\sun. An infrared spectroscopic study of a sample of M-Dwarfs outlines a method for calibrating metallicity of M-Dwarfs. Results from the newly commissionned TripleSpec spectrograph reveal that the GJ 164 system is at least of Solar metallicity. Models are not consistent with color and mass, requiring a very young age to accommodate a secondary too luminous, a scenario ruled out by the kinematics.
@article{arxiv.0809.0895,
title = {Visual orbit of GJ 164 AB},
author = {Frantz Martinache and Barbara Rojas-Ayala and Michael J. Ireland and James P. Lloyd and Peter G. Tuthill},
journal= {arXiv preprint arXiv:0809.0895},
year = {2011}
}