OPTICAL MONITORING OF THE SUPERLUMINAL QUASAR 3C-345 FROM 1984-1991

This article continues a series of publications containing results of a program of optical monitoring of OVV quasars, blazars, and similar objects (the Petersburg Quasar Monitoring Program), which has been conducted on the Byurakanskii station of the St. Petersburg Astronomical Institute since 1968. Results of long-term monitoring of the quasar 3C 345 from 1984 - 1991 are presented. The observations were conducted in the B band, and consist of 365 brightness estimates obtained over the course of 219 nights. The character of the optical variability of 3C 345 an time scales from 10's of years to 10's of minutes is discussed. In 1991, the appearance of a new large amplitude s(slow)-outburst is noted (the characteristic time for brightness variation is of order a year). This outburst is similar to outbursts in 1967 - 1968, 1970 - 1972, 1976 - 1977, and 1982 - 1983, which were associated with the emergence of superluminal components in the miiliarcsecond radio jet of 3C 345. The 1991 outburst suggests the emergence from the core of a new superluminal component. Analysis of the full known optical brightness curve for 3C 345 (1965 - 1993) shows the possible existence of a (quasi-)period of 700 days, which implies the appearance of a new brightness maximum in the 1994 observing season.