  We have obtained optical and infrared photometry of the quiescent soft X-ray
transient XTE J1118+480. In addition to optical and J-band variations, we
present the first observed H- and K_s-band ellipsoidal variations for this
system. We model the variations in all bands simultaneously with the WD98 light
curve modeling code. The infrared colors of the secondary star in this system
are consistent with a K7V, while there is evidence for light from the accretion
disk in the optical. Combining the models with the observed spectral energy
distribution of the system, the most likely value for the orbital inclination
angle is 68 +/- 2 deg. This inclination angle corresponds to a primary black
hole mass of 8.53 +/- 0.60 M_sun. Based on the derived physical parameters and
infrared colors of the system, we determine a distance of 1.72 +/- 0.10 kpc to
XTE J1118+480.

Astrophysics