Precise position measurements of Maser Sources (A Plan)

Kashima CRL 34m and Nobeyama NAO 45m telescopes are usable to mm-wavelengths and equipped with VLBI recording terminals. Preparations are in progress to connect them by VLBI. The authors plan observations of SiO and H2O masers of Mira type variable stars. Though the baseline (200km) is not long enough for mapping observations, position measurements of better than 0.001 arcsec accuracy will become possible. This will show the distribution of maser spots around the stars and motions of maser sources by the pulsation of the stars. Variable stars are important source of material to interstellar space and this observation will provide important information on the maser mechanism and mass ejection of those stars