A historical light curve of 3C 345 and its periodic analysis

All data in the B band for quasar 3C345 have been compiled into a light curve from twenty one publications, dating back to 1896; 1642 values are available. The light curve shows that 3C345 is very active and exhibits very complicated non-sinusoidal variations. Using this data we have found a period of 10.1+/-0.8 years (or 21.8+/-1.5 years) for the outbursts in 3C345. This value is in good agreement with the period of 11.4 year between outbursts found previously by Webb et al. (1988). Based on this period we can predict that the next outburst should be at its maximum around January 2002.