Stability and Radial Vibration Periods of the Hamada-Salpeter White Dwarf Models

  • John Faulkner
  • John R. Gribbin


The recent discovery by Hewish et al. 1,2 of rapidly pulsing radio sources with periods of ~ 1·337, 1·274, 1·188 and 0·2531 s has already provoked a considerable amount of activity among theoretical astrophysicists. Hewish et al. sought an explanation in terms of the radial vibrations of white dwarf or neutron star models as calculated by Meltzer and Thorne3 (hereafter MT). The apparent failure of the MT white dwarfs to pulsate in the fundamental mode with a period less than ~8s led Hewish et al. to suggest tentatively that neutron stars might possibly be responsible. While several authors have proposed other, more or less bizarre theories4–6, we shall show in this article that the white dwarf explanation may have been dismissed prematurely. We have found that the fundamental periods for the reasonably realistic white-dwarf models of Hamada and Salpeter7 can be as low as ~1·79 to ~ 2·05 s, the actual value being somewhat dependent on the composition.


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  1. 1.
    Hewish, A., Bell, S. J., Pilkington, J. D. H., Scott, P. F., and Collins, R. A., Nature, 217, 709 (1968), (Paper 1).ADSCrossRefGoogle Scholar
  2. 2.
    Pilkington, J. D. H., Hewish, A., Bell, S. J., and Cole, T. W., Nature, 218, 126 (1968), (Paper 2).ADSCrossRefGoogle Scholar
  3. 3.
    Meltzer, D. W., and Thome, K. S., Ap. J., 145, 514 (1966).ADSCrossRefGoogle Scholar
  4. 4.
    Saslaw, W. C, Faulkner, J., and Strittmatter, P. A., Nature, 217, 1222 (1968), (Paper 42).ADSCrossRefGoogle Scholar
  5. 5.
    Ostriker, J. P., Nature, 217, 1227 (1968), (Paper 39).ADSCrossRefGoogle Scholar
  6. 6.
    Burbidge, G. R., and Strittmatter, P. A., Nature, 218, 433 (1968), (Paper 43).ADSCrossRefGoogle Scholar
  7. 7.
    Hamada, T., and Salpeter, E. E., Ap. J., 134, 683 (1961).ADSCrossRefMathSciNetGoogle Scholar
  8. 8.
    Salpeter, E. E., Ap. J., 134, 669 (1961).ADSCrossRefMathSciNetGoogle Scholar
  9. 9.
    Chandrasekhar, S., Ap. J., 140, 417 (1964).ADSCrossRefzbMATHMathSciNetGoogle Scholar
  10. 10.
    Bardeen, J. M., Thome, K. S., and Meltzer, D. W., Ap. J., 145, 505 (1966).ADSCrossRefGoogle Scholar
  11. 11.
    Wolf, R. A., Phys. Rev., 137, B1634 (1965).ADSCrossRefGoogle Scholar
  12. 12.
    Chandrasekhar, S., and Tooper, R. F., Ap. J., 139, 1396 (1964).ADSCrossRefzbMATHGoogle Scholar
  13. 13.
    Chandrasekhar, S., An Introduction to the Study of Stellar Structure, second ed., 360 (Dover, 1957).zbMATHGoogle Scholar
  14. 14.
    Fowler, W. A., Ap. J., 144, 180 (1966).ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1968

Authors and Affiliations

  • John Faulkner
    • 1
  • John R. Gribbin
    • 1
  1. 1.Institute of Theoretical AstronomyUniversity of CambridgeUK

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