A Multi-wavelength, Multi-epoch Study of the Soft X-ray Transient Prototype, V616 Mon (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 Kband light curves modeled with WD98 and ELC. Combining detailed, independently run models for ellipsoidal variations due to a spotted, non-spherical 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 40.75±3. This inclination angle implies a primary black hole mass of 11.0±1.9M⊙. Subject headings: binaries: close − stars: black holes − stars: individual (V616 Mon) − stars: low mass − stars: variables: other