  We present the spectroscopic orbit of LHS 1610A, a newly discovered
single-lined spectroscopic binary with a trigonometric distance placing it at
9.9 pm 0.2 pc. We obtained spectra with the TRES instrument on the 1.5m
Tillinghast Reflector at the Fred Lawrence Whipple Observatory located on Mt.
Hopkins in AZ. We demonstrate the use of the TiO molecular bands at 7065 --
7165 Angstroms to measure radial velocities and achieve an average estimated
velocity uncertainty of 28 m/s. We measure the orbital period to be 10.6 days
and calculate a minimum mass of 44.8 pm 3.2 Jupiter masses for the secondary,
indicating that it is likely a brown dwarf. We place an upper limit to 3 sigma
of 2500 K on the effective temperature of the companion from infrared
spectroscopic observations using IGRINS on the 4.3m Discovery Channel
Telescope. In addition, we present a new photometric rotation period of 84.3
days for the primary star using data from the MEarth-South Observatory, with
which we show that the system does not eclipse.
