PARAMETERS OF THE BLACK-HOLE CANDIDATE IN THE LOW-MASS X-RAY BINARY-SYSTEM CAL 87

Optical light curves of the low mass X-ray binary system Cal 87 in the Large Magellanic Cloud have been analyzed, and on this base parameter s of the system have been determined in the frame of a model consistin g of an optical K star filling its Roche lobe and of a geometrically t hick accretion disk. The disk has a thickening (bulge) in the impact r egion of the matter stream flowing from the optical component. It has been found using all presently available data that the system's orbita l inclination is 83-degrees - 86-degrees; the mass ratio of the compon ents, for the optical star's mass M(x) congruent-to 0.6 - 0.7 M(v), is q = 9 - 11; and the mass of the compact object is M(x) congruent-to 5 .2 - 7.7 M.. It is shown that the X-ray flux observed from the system is at least approximately 40 times lower than the value necessary for the heating of the star and of the bulge derived from the light curve.