ИСТИНА

SS 433 (V1343 Aql) is a unique variable star with moving emission lines inthe spectrum which are radiated by a pair of oppositely directed and highly collimated precessing relativistic jets. It is reliably established on the base of current knowledge of distance, interstellar extinction, mass ratio, and photometric contribution of a donor A-type star, along with modern data on stellar photometry, its physical calibration, bolometric corrections, temperature calibrations, mass-luminosity relation that the compact object in this system is a neutron star with a mass close to the Chandrasekhar limit. This conclusion follows directly from the discovery of an A4-A8 I-III star in the spectrum. The mass of the neutron star is equal to 1.45 +/-0.20 M⊙ derived solely from multicolor photometry.