Astrometry of Gaia, and the 1.7 GHz and 5.0 GHz observations, as annotated. The Gaia optical position is placed at (0,0); all other positions are plotted relative to this position. The ellipses indicates the best fit Gaussian ellipse derived from a model fit to the VLBI data. Uncertainties are at 1σ level. The dashed line indicates the calibrator core shift axis along the apparent 1.7 GHz position (violet dot) is shifted; the translucent gray ellipses indicate the systematic uncertainty of that core shift (see text for details).