Is the Outflow from RT Vir Bipolar or Rotating

Abstract

We present high angular resolution observations of H2O maser proper motions in the circumstellar envelope of the semi-regular variable RT Vir. The MERLIN observations, at 12-mas angular resolution, were used to map H2O maser emission at ~2 week intervals over 10 weeks in 1996, during which period the brightness distribution changed markedly.