Rioja, M.M.RiojaMOSCADELLI, LucaLucaMOSCADELLICESARONI, RiccardoRiccardoCESARONI2023-01-032023-01-032004http://hdl.handle.net/20.500.12386/32826We present VLBI observations of the H<SUB>2</SUB>O maser emission towards a selection of massive young stellar objects (YSOs). In one of these sources, IRAS20126+4104, the measured proper motions confirm that the H<SUB>2</SUB>O masers spots are tracing the very root (∼ 100 AU) of a conical bipolar outflow emerging near the position of the embedded YSO, and are an excellent tool to investigate the structure and kinematics of the outflow/jet. We also present preliminary results of a first epoch EVN observations of a selection of 5 high-mass YSO to assess the precise association of maser spots and molecular outflows in these sources. (astro-ph/0412467)ELETTRONICOenConference paper2004evn..conf..303RFIS/05 - ASTRONOMIA E ASTROFISICA