A Massive Young Runaway Star in W49 North
  We analyzed high angular resolution 45.5 GHz images of the W49 North massive
star forming region obtained in 1998 and 2016 with the Very Large Array. Most
of the ultracompact HII regions show no detectable changes over the time
interval of the observations. However, subcomponents B1, B2, G2a and G2c have
increased its peak flux densities by values in the range of 3.8 to 21.4 \%.
Most interestingly, the cometary region C clearly shows proper motions that at
the distance of the region are equivalent to a velocity of 76$\pm$6 km s$^{-1}$
in the plane of the sky. We interpret this region as the ionized bowshock
produced by a runaway O6 ZAMS star that was ejected from the eastern edge of
Welch's ring about 6,400 years ago.
