Infrared Stars with Strong 1665/1667-MHz OH Microwave Emission

Microwave and infrared observations are presented of seven stars which have strong infrared and 1665- and 1667-MHz mainAine OH emission. The sources were selected by the fact that their I665/1667-MHz OH emission is stronger than any 1612-MHz OH emission. Five of these sources have associated H2O microwave emission. The sources are associated with M-type long-period variable stars and generally show only a small excess infrared radiation from 3 to 20 above that expected from the photosphere. The data are suggestive that both 1665/1667-MHz and 1612-MHz OH/IR stars form a continuous sequence in their intrinsic OH luminosities and their infrared properties.