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 transien t prototype V616 Mon (A0620-00). From this photometry, we find a spectral t ype of K4 for the secondary star in the system, which is consistent with sp ectroscopic observations. We present J-, H-, and K-band light curves modele d with WD98, the newest version of the Wilson-Devinney light-curve modeling code, and the ELC code. By combining detailed, independently run models fo r ellipsoidal variations due to a spotted, nonspherical secondary star and the observed ultraviolet to infrared spectral energy distribution of the sy stem, we show that the most likely value for the orbital inclination is 40. degrees 75 +/- 3 degrees. This inclination angle implies a primary black ho le mass of 11.0 +/- 1.9 M-..