A geometrical model for the SS 433 system

A geometrical model is suggested for the SS 433 stellar system, consisting of a compact object and a star revolving around each other. The system includes a precessing accretion disc around the compact object and a hotspot on the disc surface. With these elements, most of the photometric characteristics of the system previously described can be accounted for, as well as a few other observations of this star. The parameters of the model adjusted by a least squares procedure yield a mass ratio in the system m(compact)/Msub(*)>=0.8. Combined with results of radial velocity measurements by previous authors, the model parameters imply that the compact object is probably a black hole of 10-100 solar masses, the star is an early B, an O or a super-massive star. (author)