Abstract
The cataclysmic variable EX Hydrae has been observed in X-rays with Einstein Observatory. A 67 min periodic X-ray modulation has been found in the energy range .1 – 2 keV, whereas the source is approximately constant above 2 keV. The modulation is approx. in phase with the stable 47 min modulation in the optical brightness. The X-ray spectrum changes slightly with the 67 min phase but is consistent with a two component model with constant temperature only changing in relative intensity. Quasi-simultaneous optical observations were also obtained and used to extend the time base of the optical modulation. The result is indicative of a decrease in the 67 min period on a time scale of 3 106 yr. The implications for the hypothesis of a non-uniform rotating white dwarf as the origin of the 67 min optical and X-ray modulation are discussed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
