OBSERVATIONS OF BL LACERTAE FROM THE GEODETIC VLBI ARCHIVE OF THE WASHINGTON CORRELATOR

We present maps of BL Lac obtained from geodetic VLBI data from the ar chive of the Washington correlator. The observations were made from 19 96 March to 1996 November, with periods from one experiment to another as short as 1 month. The dominant structure of the maps is given by a superluminal component (C2) moving predominantly at position angle si milar to 190 degrees. At the later epochs a new superluminal component (C3) emerges from the core and moves along a trajectory at a higher p osition angle (200 degrees). We also include maps from observations ma de in 1995 June and August showing the main component (C2) in the earl y stages of its evolution, as well as an older component (C1). The pos ition angle of the component C1 is nearly the same as that of the new component C3. The component C2 shows indications of nonradial motion, which is discussed in terms of a helically distorted jet. The best fit was obtained for a half-opening angle of the jet of 2.degrees 6 and a n angle of the helical axis to the line of sight of 17 degrees.