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# ASTRONOMY

### High Angular Resolution Observations of Maser Kinematics Near Low Mass Young Stellar Objects

Alwyn Wooten (NRAO)

In regions directly coincident with forming stars water maser emission is observed when the outflowing jets of material interact with the surrounding medium. Observations of these water masers, using the VLA and VLBA dramatically reveal the innermost regions of the star formation process, with the VLBA at or below the 1-AU scale.

We have found that the water masers clearly trace the jets at these scales. The masers show proper motions on the order of 60 to 100 {\it km/s} and form within a few AU of the exciting protostar. Proper motions are thus detectable over timescales as short as several days. By observing the distributions and motions of the water masers associated with these objects we may be able to address in greater detail the collimation mechanism of the jets seen in these objects.

We will provide an overview of multi-epoch observations obtained so far by our group and other researchers on the water masers in the sources IRAS16293-2422, IRAS05413-0104 (HH212), S106FIR, and SVS13 and IRAS4 A, B in NGC1333.