DISCOVERY OF OH AND H2O MASERS IN R-AQUARII AND H1-36-ARAE

We present the first results from an all-sky maser-line survey of symb iotic Miras. Interferometric spectral-line observations of R Aqr and H 1-36 have revealed a 22-GHz water maser in the former and 1612-MHz hyd roxyl and weak 22-GHz water maser emission from the latter. H1-36 has thus become the first known symbiotic OH/IR star. We have also detecte d weak OH line emission from the vicinity of R Aqr, but we note that t here are small discrepancies between the OH- and H2O-line velocities a nd positions. These detections demonstrate unequivocally that dust can shield some circumstellar hydroxyl and water molecules from dissociat ion, even in systems that possess intense local sources of UV. Finally , we discuss some of the implications of these observations. The narro w profile of the water maser in R Aqr means that there may finally be an opportunity to determine the system's orbital parameters. We also p oint out that high-resolution synthesis observations may trace the dis tribution of dust in H1-36 and R Aqr, possibly throwing light on the m ass-loss process in symbiotic Miras and placing constraints on the amo unt of collimation experienced by UV radiation from their hot, compact companions.