1612 MHz OH survey of IRAS point sources. I. Observations made at Dwingloo, Effelsberg and Parkes.

. - We have observed 2703 IRAS point sources at the 1612 MHz transition of OH and detected 738 OH/IR stars; 597 of these are new discoveries. The IRAS sources were selected on the basis of their infrared colours using the 12, 25 and 60 iim fluxes. The survey is 70% complete for IRAS point sources in the southern hemisphere (8 < 10o), with infrared colours: log (f m/A2 m) > -0.2 and log (f m/fi2 m) < 0.6 and having a 12 ttm flux exceeding 3 Jy. The majority of the OH profiles show twin peak maser features, characteristic of emission from an expanding circumstellar shell. The detection statistics of the survey are discussed. Detailed statistical analyses of the OH/IR star sample are made in a subsequent paper. Key words: OH maser - OH/IR stars.