Advertisement

A search for hot pulsators similar to PG 1159-035 and the central star of K 1-16

  • Howard E. Bond
  • Albert D. Grauer
  • James Liebert
  • Thomas Fleming
  • Richard F. Green
Degenerate and Pre-Degenerate Variables
Part of the Lecture Notes in Physics book series (LNP, volume 274)

Abstract

The four known pulsators lie at 80, 000 K < Teff < 160, 000 K and 6 < log g < 8, or about 1.5 < log L/L < 3, in the HR diagram. Our non-pulsating DO white dwarfs may be outside the temperature range of the instability strip, being slightly cooler than the GW Vir pulsators (or slightly hotter in the case of H 1504+65).The non-pulsating planetary nuclei have high temperatures and show helium and carbon features in their spectra, but are more luminous than the pulsators, since they have decidedly lower surface gravities.

More puzzling are our null results for the three PG objects 1151-029, 1424+535, and 1520+525, which have spectra closely resembling those of the G W Vir pulsators (Wesemael et al. 1985). Possibly the pulsational instability may be critically sensitive to the CNO abundances (which have not yet been determined in these objects) or to temperature or surface-gravity differences too small to be apparent in the spectra.

A more detailed version of this paper has been submitted for publication in The Astrophysical Journal.

Keywords

Central Star Planetary Nebula Detailed Version Astrophysical Journal Instability Strip 
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.

References

  1. Bond, H.E., Grauer, A.D., Green, R.F., and Liebert, J. 1984, Ap. J., 279, 751.Google Scholar
  2. Grauer, A.D., and Bond, H.E. 1981, Pub. A.S.P., 93, 388.Google Scholar
  3. -1984, Ap. J., 277, 211.Google Scholar
  4. McGraw, J.T., Starrfield, S., Liebert, J., and Green, R.F. 1979, in IAU Coll. No. 59, White Dwarfs and Variable Degenerate Stars, eds. H.M. Van Horn and V. Weidemann (Rochester: Univ. of Rochester Press), p. 377.Google Scholar
  5. Starrfield, S., Cox, A.N., Kidman, R.B., and Pesnell, W.D. 1984, Ap. J., 281, 800.Google Scholar
  6. Wesemael, F., Green, R.F., and Liebert, J 1985, Ap. J. Suppl., 58, 379.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1987

Authors and Affiliations

  • Howard E. Bond
    • 1
  • Albert D. Grauer
    • 2
  • James Liebert
    • 3
  • Thomas Fleming
    • 3
  • Richard F. Green
    • 4
  1. 1.Space Telescope Science InstituteUSA
  2. 2.University of ArkansasLittle Rock
  3. 3.University of ArizonaUSA
  4. 4.Kitt Peak National ObservatoryUSA

Personalised recommendations