Some features of the x-ray source on Cyg X-3

Data from the Copernicus satellite are presented which show that the 4.8 hour light curve of Cyg X-3 has been relatively stable in period, shape and amplitude since the observation of the first giant radio outburst in 1972 September. A pulse height spectrum of the source obtained by the Ariel 5 satellite in the 1.5 to 26 keV energy band shows convincing evidence for line emission at about 6.5 keV. The strength of this feature varies in phase with the 4.8 hour continuum modulation, but there is no simple long term relation with the mean continuum intensity per 4.8 hour cycle. Evidence will be presented which indicates that the average 2 to 6 keV intensity of Cyg X-3 has been higher by a factor of approximately 3 since the onset of the radio flares