Trigonometric distance and proper motions of H2O maser bowshocks in AFGL
  5142
  We present the results of multi-epoch VLBI observations of water masers in
the AGFL 5142 massive star forming region. We measure an annual parallax of
$\pi=0.467 \pm 0.010$ mas, corresponding to a source distance of
$D=2.14^{+0.051}_{-0.049}$ kpc. Proper motion and line of sight velocities
reveal the 3D kinematics of masers in this region, most of which associate with
millimeter sources from the literature. In particular we find remarkable
bipolar bowshocks expanding from the most massive member, AFGL 5142 MM1, which
are used to investigate the physical properties of its protostellar jet. We
attempt to link the known outflows in this region to possible progenitors by
considering a precessing jet scenario and we discuss the episodic nature of
ejections in AFGL 5142.
