Bottom right and top left: Positions (marked with X symbols) of the water maser spots measured with the VLBA in VLA 1 and VLA 2. Arrow lengths represent the corresponding measured proper motion vectors, and their color code indicates the LSR velocity of the individual features.
Bottom left: 1.3 cm continuum (contour plot) and water maser emission (triangles) in VLA 1 and VLA 2, detected previously with the VLA in 1996, together with the VLBA water maser spots (X symbols).
Three top right panels: Close-up of three small sections of the VLA 2 water maser shell. Maser positions measured with the VLBA are marked by plus, asterisks, and X symbols, corresponding to the first, second, and third observed epochs, respectively. The LSR velocity (in km/s) for each spot is labeled. The accuracy in the relative positions of the VLBA maser spots within each epoch is better than 0.05 milliarcsecons.