The X-ray modulation of CYG X-3.
Abstract
Results of three 40d COS-B X-rays observations of Cyg X-3 are presented. The shape of the light curve, although variable from cycle to cycle, is generally very stable when averaged over many cycles. During one four-week period, however, a different mean light curve was observed. It is shown that the correlated behavior of amplitude, average level, and mean shape of the light curve can be explained in terms of an eclipsing binary surrounded by scattering gas, which becomes transparent when the source intensity increases. In the highest-quality part of the data, a variation is found in the phase of arrival of the minimum of the light curve, which suggests an approximately 20d periodicity. Apsidal motion of an orbit with e of about 0.03 is suggested as a possible explanation of this effect.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- September 1981
- Bibcode:
- 1981A&A...101..299B
- Keywords:
-
- Eclipsing Binary Stars;
- Light Curve;
- Stellar Radiation;
- X Ray Sources;
- Cygnus Constellation;
- Modulation;
- Astronomy