, Volume 51, Issue 7, pp 710–720 | Cite as

X-rays from the Sun

  • C. U. Keller


X-ray astronomy began in 1948 with the first detection of X-rays from the Sun. Astronomical X-ray observations need to be performed from high-altitude rockets and satellites because the Earth's atmosphere absorbs X-rays. Currently about 100,000 X-ray sources are known all over the sky. The Sun is by far the strongest source. The outermost solar atmosphere, the corona, emits X-rays due to its high temperature of a few million K. Solar X-ray emission is highly variable. Eruptions lead to variations of the X-ray flux on time scales of minutes. The average X-ray flux varies with the 11-year sunspot cycle by a factor of about 1000. Solar X-rays have a profound influence on the Earth's upper atmosphere.

Key words

X-rays astronomy sun corona solar magnetic fields satellites detectors 


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  1. 1.
    Bahcall, J. N., Neutrino Astrophysics. Cambridge University Press, Cambridge 1989.Google Scholar
  2. 2.
    Baum, W. A., Johnson, F. S., Oberly, J. J., Rockwood, C. C., Strain, C. V., and Tousy, R., Solar Ultraviolet Spectrum to 88 Kilometers. Phys. Rev.70 (1946) 781–782.CrossRefGoogle Scholar
  3. 3.
    Biermann, L., Kometenschweife und solare Korpuskularstrahlung. Z. Astrophys.29 (1951) 274–286.Google Scholar
  4. 4.
    Blake, R. L., Chubb, T. A., Friedman, H., and Unzicker, A. E., Spectral and photometric measurements of solar X-ray emission below 60 Å. Astrophys. J.142 (1965) 1–12.CrossRefGoogle Scholar
  5. 5.
    Bohlin, J. D., Frost, K. J., Burr, P. T., Guha, A. K., and Withbroe, G. L., Solar Maximum Mission. Sol. Physics65 (1980) 5–14.CrossRefGoogle Scholar
  6. 6.
    Burnight, T. R., Soft X-Radiation in the Upper Atmosphere. Phys. Rev.76 (1949) 165.Google Scholar
  7. 7.
    Burnight, T. R., Ultraviolet Radiation and X-Rays of Solar Origin, in: Physics and Medicine of the Upper Atmosphere, chap. 13. Eds C. S. White and O. O. Benson Jr. University of New Mexico, Albuquerque 1952.Google Scholar
  8. 8.
    Compton, W. D., and Benson, C. D., Living and working in space: A history of Skylab. NASA SP-4208, Washington DC 1983.Google Scholar
  9. 9.
    Culhane, J. L., and Sanford, P. W., X-ray Astonomy. Charles Scribner's Sons, New York 1981.Google Scholar
  10. 10.
    Doschek, G. A., Solar Instruments on the P78-1 spacecraft. Sol. Physics86 (1983) 9–17.CrossRefGoogle Scholar
  11. 11.
    Eddy, J. A., A new sun: The Solar Results From Skylab. NASA SP-402, Washington DC 1979.Google Scholar
  12. 12.
    Giacconi, R., Gursky, H., Paolini, F. R., and Rossi, B. B., Evidence for X Rays From Outside the Solar System. Phys. Rev. Lett. 9 (1962) 439–443.CrossRefGoogle Scholar
  13. 13.
    Golub, L., Herant, M., Kalata, K., Lovas, I., Nystrom, G., Pardo, F., Spiller, E., and Wilczynski, J., Sub-arcsecond observations of the solar X-ray corona. Nature344 (1990) 842–844 1990.CrossRefGoogle Scholar
  14. 14.
    Hufbauer, K., Exploring the Sun: Solar Science since Galileo. Johns Hopkins University Press, Baltimore 1991.Google Scholar
  15. 15.
    Newell, H. E., High Altitude Rocket Research. Academic Press Inc., New York 1953.Google Scholar
  16. 16.
    Ogawara, Y., Takano, T., Kato, T., Kosugi, T., Tsuneta, S., Watanabe, T., Kondo, I., and Uchida, Y., The Solar-A Mission: An Overview. Sol. Physics136 (1991) 1–16.CrossRefGoogle Scholar
  17. 17.
    Parker, E. N., Dynamics of the Interplanetary Gas and Magnetic Field. Astrophys. J.128 (1958) 664–676.CrossRefGoogle Scholar
  18. 18.
    Phillips, K. J. H., Guide to the Sun. Cambridge University Press, Cambridge UK 1992.Google Scholar
  19. 19.
    Ramsey, B. D., Austin, R. A., and Decher, R., Instrumentation for X-Ray Astronomy. Space Science Review69 (1994) 139–204.CrossRefGoogle Scholar
  20. 20.
    Stix, M., The Sun: An Introduction. Springer Verlag, Berlin 1989.Google Scholar
  21. 21.
    Tanaka, Y., Introduction to Hinotori. Sol. Physics86 (1983) 3–6.CrossRefGoogle Scholar
  22. 22.
    Waldmeier, M., Die Sonnenkorona I. Birkhäuser, Basel 1951.Google Scholar
  23. 23.
    Waldmeier, M., Die Sonnenkorona II. Birkhäuser, Basel 1957.Google Scholar
  24. 24.
    Wolter, H., Annln Phys.10 (1952) 94.Google Scholar

Copyright information

© Birkhäuser Verlag 1995

Authors and Affiliations

  • C. U. Keller
    • 1
  1. 1.National Solar ObservatoryNational Optical Astronomy ObservatoriesTucsonUSA

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