VLA observations of brightness enhancements moving along the axis of the Cep A HW2 thermal jet

We analyze sensitive, higli angular resolution (0″.3) Very Large Array observations made at 6-cm of the thermal jet Cep A HW2 in two epochs separated by 1.3 years. The subtraction of the maps made at the two epochs clearly shows the presence of brightness enhancements that travel in the jet at a velocity of 950±150 km s-1. We also use these results to estimate an accurate position for the exciting star of this jet.