Variability of Soft X-Ray Emission of Ex Hydrae Observed with Einstein Observatory

  • A. Kruszewski
  • R. Mewe
  • J. Heise
  • T. Chlebowski
  • W. van Dijk
  • R. Bakker
Conference paper
Part of the Astrophysics and Space Science Library book series (ASSL, volume 98)


The cataclysmic variable star EX Hydrae has been observed with the High Resolution Imager (HRI) and the Imaging Proportional Counter (IPC) onboard the Einstein Observatory. The X-ray position is coincident within 3 arcsec of the optical position as measured on Schmidt survey plates. During a 15 1/2 hour observation with IPC we have searched for a modulation of the X-ray flux. Strong evidence for a 67 min period (one of two known optical periods) has been found in the energy range 0.1–3.5 keV with the IPC. The time dependence of modulations is used to discuss a model and evolutionary status of this close binary system.


Accretion Disc White Dwarf High Resolution Imager Monthly Notice Optical Position 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. Bath, G.T., Pringle, J.E., Whelan, J.A.J.: 1980, Monthly Notices Roy. Astron. Soc. 191, 185.ADSGoogle Scholar
  2. Breysacher, J., Vogt, N.: 1980, Astron. Astrophys. 87, 349.ADSGoogle Scholar
  3. Chiappetti, L., Tanzi, E.G., Treves, A.: 1980, Space Sci. Rev. 27, 3.ADSCrossRefGoogle Scholar
  4. Cordova, F.A., Riegler, G.R.: 1979, Monthly Notices Roy. Astron. Soc. 188, 103.ADSGoogle Scholar
  5. Deeming, T.J.: 1975, Astrophys. Space Sc. 36, 137.MathSciNetADSMATHCrossRefGoogle Scholar
  6. Cowley, A.P., Hutchings, J.B., Crampton, D.: 1981, Astrophys. J. 246, 489.ADSCrossRefGoogle Scholar
  7. Giacconi, R. et al: Astrophys. J. 230, 540.Google Scholar
  8. Grindlay, J.E.: 1980, private communication.Google Scholar
  9. Hutchings, J.B., Crampton, D., Cowley, A.P., Thorstensen, J.R., Charles, P.A: 1981, preprint.Google Scholar
  10. King, A.R, Lasota, J.P.: 1979, Monthly Notices Roy. Astron. Soc. 188, 653.ADSGoogle Scholar
  11. Kraft, R.P., Krzeminski, W.: 1962, in Annual Report of the Director of Mount Wilson and Palomar Observatories (1961–1962), p. 20.Google Scholar
  12. Krzeminski, W., Priedhorsky, W., Tapia, S.: 1981, private communication.Google Scholar
  13. Masters, A.R., Pringle, J.E., Fabian, A.C., Rees, M.J.: 1976, Monthly Notices Roy. Astron. Soc. 178, 501.ADSGoogle Scholar
  14. Motch, C.: 1981, ESO preprint no. 135.Google Scholar
  15. Papaloizou, J., Pringle, J.E.: 1980, Monthly Notices Roy. Astron. Soc. 190 (Short Comm.), 13P.ADSGoogle Scholar
  16. Patterson, J.: 1979a, Astrophys. J. Letters 233, L13.ADSCrossRefGoogle Scholar
  17. Patterson, J.: 1979b, Astrophys. J. 234, 978.ADSCrossRefGoogle Scholar
  18. Patterson, J.: 1979c, Astron. J. 84, 804.ADSCrossRefGoogle Scholar
  19. Patterson, J.: 1981, Santa Cruz Summer Workshop on Cataclysmic Binarias.Google Scholar
  20. Patterson, J., Branch, D., Chincarini, G., Robinson, E.L.: 1980, Astrophys. J. Letters 240, L133.ADSCrossRefGoogle Scholar
  21. Patterson, J., Garcia, N.: 1980, IAU Circ. No. 3514.Google Scholar
  22. Patterson, J., Price, C.M.: 1981, Astrophys. J. Letters, 243, L83.ADSCrossRefGoogle Scholar
  23. Quinley, R., Africano, J.L., Rogers, W.: 1980, Bull.Am.Astr.Soc. 12, 848.ADSGoogle Scholar
  24. Rappaport, S., Joss, P.C.: 1977, Nature 266, 683.ADSCrossRefGoogle Scholar
  25. Robinson, E.L., Nather, R.E., Patterson, J.: 1978, Astrophys. J. 219, 168.ADSCrossRefGoogle Scholar
  26. Schwartz, D.A., Bradt, H., Biel, U., Doxey, R.E., Fabbiano, G., Griffiths, R.E., Johnston, M.D., Hirgon, B.: 1978, Astron. J. 84, 1560.ADSCrossRefGoogle Scholar
  27. Sherrington, M.R., Lawson, P.A., King, A.R., Jameson, R.F.: 1980, Monthly Notices Roy. Astron. Soc. 191, 185.ADSGoogle Scholar
  28. Shipman, H.L.: 1977, Astrophys. J. 213, 138.ADSCrossRefGoogle Scholar
  29. Stockman, H., Liebert, J., Tapia, S., Green, R., Williams, R., Ferguson, D., Szkody, P.: 1981, IAU Circ, No. 3616.Google Scholar
  30. Vogt, N.: 1980, Astron. Astrophys. 88, 66.ADSGoogle Scholar
  31. Vogt, N., Krzeminski, W., Sterken, C.: 1980, Astron. Astrophys. 85, 106.ADSGoogle Scholar
  32. Walker, M.F.: 1956, Astrophys. J. 123, 68.ADSCrossRefGoogle Scholar
  33. Warner, B.: 1972, Monthly Notices, Roy Astron. Soc. 158, 425.ADSGoogle Scholar
  34. Warner, B., McGraw, J.T.: 1981, Monthly Notices Roy. Astron. Soc. 196 (Short Comm.), 59P.ADSGoogle Scholar
  35. Watson, M.G., Sherrington, M.R., Jameson, R.F.: 1978, Monthly Notices Roy. Astron. Soc. 184 (Short Comm.), 79P.ADSGoogle Scholar
  36. White, N.E., Marshall, F.E.: 1980, IAU Circ. No. 3514.Google Scholar

Copyright information

© D. Reidel Publishing Company 1982

Authors and Affiliations

  • A. Kruszewski
    • 1
    • 2
  • R. Mewe
    • 3
  • J. Heise
    • 3
  • T. Chlebowski
    • 4
  • W. van Dijk
    • 3
  • R. Bakker
    • 5
  1. 1.Warsaw University ObservatoryWarsawPoland
  2. 2.European Southern ObservatoryGarchingGermany
  3. 3.Space Research LaboratoryUtrechtThe Netherlands
  4. 4.Harvard-Smithsonian Center for AstrophysicsCambridgeUSA
  5. 5.Astronomical InstituteUniversity of AmsterdamAmsterdamThe Netherlands

Personalised recommendations