Kinematic structure of the U Ori envelope. Position of the null velocity line (left panel) and radial distributions of V _a (right panel, solid line), V _e (right panel, dashed line) and V _rot (right panel, dash-dotted line) velocities are shown. Rotational and expanding velocities estimated from comparison of IOTA images and water maser map (Vlemmings et al. 2005) are marked with filled circles and a triangle, respectively.