Component distance from the core component (set to zero) as a function of time (see Table A.1 for model parameters). For the identified components (colored symbols), the error bars show the systematic errors, which are defined as 0.5 × b_maj for resolved components. For unresolved components, the resolution limit is used (Kovalev et al. 2005). A linear regression fit to associated components is shown. Components not included in the fit are shown in gray. We note, in particular, the components in the region of the “tuning fork” are excluded since the region is too complex. The mean apparent speed is determined for components J3 to J10.