A multiwavelength, multiepoch study of the soft X-ray transient prototype, V616 Monocerotis (A0620-00)

We have obtained optical and infrared photometry of the soft X-ray transient prototype V616 Mon (A0620-00). From this photometry, we find a spectral type of K4 for the secondary star in the system, which is consistent with spectroscopic observations. We present J-, H-, and K-band light curves modeled with WD98, the newest version of the Wilson-Devinney light-curve modeling code, and the ELC code. By combining detailed, independently run models for ellipsoidal variations due to a spotted, nonspherical secondary star and the observed ultraviolet to infrared spectral energy distribution of the system, we show that the most likely value for the orbital inclination is 40.degrees 75 +/- 3 degrees. This inclination angle implies a primary black hole mass of 11.0 +/- 1.9 M-..