Position of HD 163296 at the different observing epochs. The dashed line represents the proper motions from the Hipparcos measurement (J1991.25) to 2012, with respective proper motion error ellipses at 1, 2, and 3σ from the predicted positions. The black dot indicates our position estimate for the star at epoch 2012.5 based on the peak of the image in Band 7, while the red dot is the peak of the VLA image at 9 mm in 2011.5. The error bars are given by the astrometric accuracy of 0.1 arcsec for ALMA and 0.02 arcsec for VLA. The blue solid line represents the proper motions calculated from a least-squares regression between Hipparcos measurements and the observations.