OH/IR Sources as an Example of a Successful Simultaneous Radio and Infrared Programme

In the Messenger No. 6, September 1976, W.A. Sherwood reported on the successful discovery of infrared counterparts of type 1I OH/IR sources previously found in the Onsala OH survey by A. Winnberg et al. The frequency of discovering the IR counterparts was about 50 % at that time. In the meantime our detector has been improved in sensitivity by E. Kreysa and our frequency of detection with the new photometer has risen to 80 % of a sam pie of 40 OH sou rces without having to use a larger telescope.