A search for water maser emission from post-AGB stars

We have used the Tidbinbilla 70-m antenna to search for 22 GHz H₂O maser emission from a sample of 85 evolved stars. 21 detections were made. Of these 15 were from massive AGB stars. High-velocity H₂O maser emission was detected from five sources, of which four are post-AGB stars. Three of the high-velocity sources, b292 (IRAS 18043-2116), d46 (IRAS 15445-5449), and d62 (IRAS 15544-5332) were new discoveries. d46 is also a source of non-thermal radio continuum emission. The high-velocity H₂O maser emission and the radio continuum from post-AGB stars are probably associated with shocks that form from wind-wind interactions.