Abstract

We present an optical intraday variability (IDV) study of S5 0716+714 carried out over 52 nights. The source showed detectable variations (>0.05 mag) in 80% of the nights. Typical variation rates of 0.02 mag/hour have been found to last on average 4 hours, with the average rising rate faster than the decreasing one. A maximum rising rate of 0.16 mag/hour has been observed. If the luminosity variation is due to jittering in the jet direction, a comoving dθ/dt rate of ∼100 arcsec/hour is required, assuming for the jet θ ∼ 7° and Γ ∼ 14.