SiO Maser Observations - VLBI and Polarimetry

The spatial distribution and polarization characteristics of the SiO (v=1, J=1-0) maser emission from several late type stars have been observed. The spatial distribution, derived from VLBI observations, generally shows a number of emitting regions but no clear velocity pattern or geometry. Some of these regions have well defined polarization characteristics. The results of high spatial resolution polarization measurements of RCas are similar to the lower spatial resolution polarimetry performed on this source.