We use Hubble Space Telescope Fine Guidance Sensor astrometry and
high-cadence radial velocities for HD136118 from the HET with archival data
from Lick to determine the complete set of orbital parameters for HD136118b. We
find an orbital inclination for the candidate exoplanet of i_{b} = 163.1 +- 3.0
deg. This establishes the actual mass of the object, M_{b} = 42^{+11}_{-18}
MJup, in contrast to the minimum mass determined from the radial velocity data
only, M_{b}sin{i} ~ 12 MJup. Therefore, the low-mass companion to HD 136118 is
now identified as a likely brown dwarf residing in the "brown dwarf desert".Comment: 35 pages, 12 figures, 10 tables. Accepted for publication in
Astrophysical Journa