Visual orbit of GJ 164 AB

TL;DR

This paper presents high-resolution observations of the GJ 164 AB binary system, determining component masses and metallicity, and discusses implications for stellar models and age estimates.

Contribution

It provides a model-independent mass measurement of GJ 164B and introduces a method for calibrating M-Dwarf metallicity using infrared spectroscopy.

Findings

Mass of GJ 164B is 0.086 ± 0.007 solar masses.

GJ 164 system has at least solar metallicity.

Models require a very young age to match observations, which is inconsistent with kinematic data.

Abstract

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 \pm 0.007 M_{\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.