2001AJ....122..971G

We have obtained infrared photometry for the soft X-ray transient GU Mus. We present J- and K_s-band light curves modeled with WD98, the newest version of the Wilson-Devinney light curve-modeling code. Using detailed models for the expected ellipsoidal variations due to the nonspherical secondary star, we show that the most likely value for the orbital inclination is 54°±1°.5. This inclination angle is consistent with those previously published, but it has a much smaller error. This inclination implies a primary black hole mass of 6.95±0.6 M_☉. While we do not see any evidence for contamination of our infrared light curves from other sources in the system, a conservative model with a contamination level of 15% increases the uncertainty in the inclination angle to 54⁺⁴_–1.5 deg.