We analyze simultaneous radio-X-ray data of Cygnus X-1 from the Ryle
telescope (RT) and RXTE over more than 4 a. We show that apparent correlations
on short time scales in the lightcurves of Cyg X-1 are probably the
coincidental outcome of white noise statistics.Comment: 1 page, 1 figure. Proceedings of the IAU Colloquium 194 "Compact
Binaries in the Galaxy and Beyond", to be published in: Revista Mexicana de
Astronomia y Astrofisica, Conference Serie