THE SUPERCRITICAL ACCRETION DISK OF SS-433

The structure of the SS433 supercritical accretion disk derived from s pectral and photometric data is described. In the disk plane, gas outf lows at a velocity of about 100-150 km/s, while above the disk plane, the velocity increases sharply and reaches approximate to 1500 km/s at polar angle approximate to 60 degrees. The outer parts of the accreti on disk are involved in the precessional motion, which means that the slaved disk precession model is correct. There is complex periodic var iability in the radial velocities of SS433. Apart from the well-known precessional and orbital variability, the strongest cycle is 1/7 of th e precession period, P-7 = 23.228 +/- 0.005 days. This is interpreted as evidence for a spiral shock in the accretion disk. The He II lambda 4686 line consists of two components: a stream-formed narrow Gaussian profile and a broad double-peaked one. The latter is completely eclip sed at phase 0.0. Its blue and red peaks are probably emitted in gaseo us cocoons around the bases of the relativistic jets. A correct value of the mass function has been found, which shows that the optical star is massive. The relativistic star's mass is estimated to be M-x great er than or similar to 6M..