EXCITED OH 4.7-GHZ MASERS ASSOCIATED WITH IRAS FAR-INFRARED SOURCES .2.

A sample of 85 far-infrared sources selected from the IRAS Point Sourc e Catalog has been searched for maser emission from excited OH in the (2) Pi(1/2) J = 1/2 state, in the three transitions at 4765, 4750 and 4660 MHz. Four new detections were made at 4765 MHz, including one sou rce where ground-state OH maser emission has not been reported. One ne w detection was made at 4660 MHz. This source OH 351.78 - 0.54 is rema rkable in that it was detected only at 4660 MHz, and not at 4765 or 47 50 MHz. Positions were measured for the new detections and for six pre viously known 4.7-GHz maser sources. In some cases the excited OH 4.7- GHz positions are significantly different from the positions of previo usly known ground-state OH 18-cm masers. The 4.7-GHz sources are among the brighter far-infrared sources in the IRAS sample. In most cases t hey are also OH 18-cm masers. There is a strong association between OH 4.7-GHz emission and OH 18-cm maser emission in the 1720-MHz transiti on. More than half of the 4.7-GHz masers that were examined for variab ility showed strong variations on a time-scale of a year.