Overlay of molecular masers detected around W51e8 onto the total intensity (0th moment) map of the (6, 6) inversion transition of NH₃ (gray scale and white+black contours). The circles show positions and the arrows indicate proper motions of OH masers (Fish & Reid 2007) (top panel), and H₂O masers (Sato et al. 2010) (bottom panel), respectively, both measured with the VLBA. Colors denote l.o.s. velocity (color scale on the right-hand side in each panel) and the scale for the proper motion amplitude is given in the bottom right corner of each panel (both in km s^-1). The NH₃ emission is shown with white contours, representing 20% to 100% with steps of 20% of the line peak for the (6, 6) line, 107 mJy beam^-1 km s^-1. The red contour indicates the 3 mJy flux level per beam (corresponding to ~4σ where σ ~ 0.7 mJy beam^-1) for the 25 GHz continuum emission. Besides W51e1 to the SW, a peak of the radio continuum falls at the peak of the total intensity map of the most highly excited NH₃ transitions (13, 13), which are indicated with cyan contours. We assume that its position pinpoints a high-mass YSO at the center of W51e8, driving both a fast H₂O maser outflow and a more slowly expanding OH maser shell.