The first IR measurements have been presented on 24 proposed or confirmed optical/IR counterparts to X-ray binary systems. A further 6 sources have new IR measurements. Together they represent the largest coherent group of southern hemisphere, X-ray binary sources studied and provide valuable data to help in the understanding of the behaviour of these transient X-ray binary systems. One important conclusion is that the Be star systems show greater variability than the supergiant systems - the Be systems have an average F value of 0.052, whereas the supergiant average is 0.030. This may well provide a useful method of discriminating between the two systems.
Acknowledgements
We are grateful to the SAAO for the allocations of observing time and to the very helpful support of the staff. We also thank Chris Everall for helping with some of the early observations, and Paul Roche and Pablo Reig for comments on the paper. We are particularily grateful to the constructive refereeing of Dr. F. Haberl. This research has made use of the Simbad database, operated at CDS, Strasbourg, France.