Pulsar Condition in White Dwarf Stars

  • Werner Israel


According to the recently proposed “astronomical sandglass model” of the pulsed radio sources1 a pulsar is a neutron star at the critical mass limit for gravitational instability. Any loss of stability resulting in incipient collapse is quickly restored by the remaining nuclear resources, which, it was assumed, can still generate thermal pulses of about 1034 ergs. Because the radius of a critical neutron star is 106 cm, the resulting energy density is of order 1016 erg cm-3, corresponding to X-ray phonons. The degenerate interior of the star has a very high thermal conductivity and the X-ray pulse passes rapidly to the surface, where it blows off the thin (~1012 g) non-degenerate outer layer with less than escape velocity. After about a second this ejected material has all trickled back to the surface, triggering off the next instability.


  1. 1.
    Israel, W., Nature, 218, 755 (1968), (Paper 33).ADSCrossRefGoogle Scholar
  2. 2.
    Chandrasekhar, S., Introduction to the Study of Stellar Structure (Dover, New York, 1957).zbMATHGoogle Scholar
  3. 3.
    Kraft, R. P., Adv. Astro. Astrophys., 3, 43 (1963).CrossRefGoogle Scholar
  4. 4.
    Shklovsky, I. S., Astrophys. J. Lett., 148, L1 (1967).ADSCrossRefGoogle Scholar
  5. 4a.
    Prendergast, K. H., and Burbidge, G. R., Astrophys. J. Lett., 151, L83 (1968).ADSCrossRefGoogle Scholar
  6. 5.
    Kopal, Z., in Vistas in Astronomy (edit. by Beer, A.), 2, 1491 (Pergamon Press, London, 1956).Google Scholar
  7. 6.
    Schatzman, E., in Stellar Structure (edit. by Aller, L. H., and McLaughlin, D. B.), 327 (University of Chicago Press, Chicago, 1963).Google Scholar
  8. 7.
    Huang, S. S., and Struve, O., Occasional Notes, Roy. Astro. Soc, 19, 161 (1957).Google Scholar
  9. 8.
    Payne-Gaposhkin, C., The Galactic Novae (North-Holland Pub. Co., Amsterdam, 1957).Google Scholar
  10. 9.
    Becklin, E. E., and Neugebauer, G., Astrophys. J., 151, 145 (1968).ADSCrossRefGoogle Scholar
  11. 10.
    Burbidge, G. R., Nature, 190, 1053 (1961).ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1968

Authors and Affiliations

  • Werner Israel
    • 1
  1. 1.Dublin Institute for Advanced StudiesDublinIreland

Personalised recommendations