A change in light curve asymmetry and the ephemeris of CYG X-3.

van der Klis, M.; Bonnet-Bidaud, J. M.

Netherlands, France

Abstract

Cygnus X-3 was observed in the 2-12 keV range for 40 days in May-June 1980. The mean 4.8 h light curve was seen to change significantly in a way suggestive of the existence of an underlying binary with an eclipse duration of 40 percent of the period. The observed time of X-ray minimum was found to increase the level of confidence of a period derivative when compared to the earlier measurements.

1981 Astronomy and Astrophysics
COS-B 89