SPIRAL SHOCKS AND SUBDAY VARIABILITY IN SS-433

We perform a two-dimensional numerical simulation of fluid hydrodynamics in the accretion disk of the SS 433 system. We show that the disk must have quasi-stationary two-armed spiral shocks. We calculate the blackbody spectrum of the disk. The spectrum clearly shows subday variabilities in the optical component. Future observation of such a variability could throw more light on the nature of the SS 433 system. We suggest that the spiral shocks provide the necessary viscosity to sustain a supercritical accretion.