VELOCITIES AND LIFETIMES IN THE VLBI JET OF 3C-273

High-resolution VLBI observations at 10.7 GHz are presented for four e pochs between 1988.17 and 1991.17. Three superluminal components, not seen in previous maps at this frequency, were detected. The ejection t imes of two of these are well correlated with the occurrence of strong hares at radio and infrared wavelengths. The third component was shor t-lived, and was detected only in the first map at a distance of 0.6 m as from the core. Differences in velocity, combined with the existence of short-lived components could explain the gaps observed in the jet in lower frequency maps. The analysis of all the data available in the literature shows that the velocities of the individual components did not change with time, but varied from one component to another, in th e range of v/c = 4.9h(-1) to 7.7h(-1). While some components seem to f ollow the same curved path in the sky, two of them, first seen between 1983 and 1985 show clearly a different behaviour.