Optical manifestations of superluminal expansion of components belonging to the millisecond radio structure in the quasar 3C 345

All the available data on superluminal variations in the millisecond radio structure of the quasar 3C 345 at frequencies of 5-15 GHz over the period 1971-1982 are compared with the optical variability of that source. A correlation is found between optical s-outbursts observed in the object since 1966 and the variation in the total radio flux density at 10.7 GHz with time delays of 400-1000 days in radio outbursts observed in the object. From this is inferred a connection between the radio outbursts of comparatively small amplitudes with the emergence of moving jet components. It is concluded that one of the reasons for optical variability in extragalactic objects is the phenomenon of jet ejections from the nucleus. (C.D.)