Hostname: page-component-8448b6f56d-t5pn6 Total loading time: 0 Render date: 2024-04-25T05:38:48.717Z Has data issue: false hasContentIssue false

The Surface Gravities of Be Stars

Published online by Cambridge University Press:  14 August 2015

Geraldine J. Peters*
Affiliation:
Dept. of Astronomy, University of California, Los Angeles, Calif., U.S.A.

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

In an attempt to shed some light on the origin of the material in the envelopes of Be stars, surface gravities were determined for 30 objects by comparing their observed profiles of Hγ and Hδ with those computed from the Princeton model atmospheres and the VCS theory of hydrogen line broadening. The program stars are predominately well-known Be stars and display a wide range of envelope spectra and v sin i. The mean and range in log g for the Be stars appear to be identical to that obtained from a similar analysis on non-Be stars. No correlation was found between log g and Hα emission strength or the strength and/or presence of emission of Fe II, O I λ 7774 Å, or the infrared Ca ii triplet. The suggestion made by Schild (1973) and Schild et al. (1974) that the extreme Be stars are in the post main sequence phase of rapid core contraction is weakened by the fact that there are several members of the class which have log g ≥ 3.8. All shell stars considered in the program appear to have low values of log g (≤3.5). Some possible explanations for this occurrence are discussed.

Type
Part 1: Observations of Be Stars
Copyright
Copyright © Reidel 1976 

References

Blanco, V. M., Demers, S., Douglass, G. G., and Fitzgerald, M. P.: 1968, Publ. U.S. Naval Obs. 21.Google Scholar
Bodenheimer, P. and Ostriker, J. P.: 1973, Astrophys. J. 180, 159.CrossRefGoogle Scholar
Burbidge, G. R. and Burbidge, E. M.: 1953, Astrophys. J. 117, 407.Google Scholar
Crampin, J. and Hoyle, F.: 1960, Monthly Notices Roy. Astron. Soc. 120, 33.Google Scholar
Feinstein, A.: 1974, Monthly Notices Roy. Astron. Soc. 169, 171.CrossRefGoogle Scholar
Heap, S. R.: 1975, personal communication.Google Scholar
Johnson, H. L.: 1966, Ann. Rev. Astron. Astrophys. 4, 193.Google Scholar
Johnson, H. L. and Mitchell, R. I.: 1958, Astrophys. J. 128, 31.Google Scholar
Kodaira, K. and Scholz, M.: 1970, Astron. Astrophys. 6, 93.Google Scholar
Koubsky, P.: 1975, IAU Circ. No. 2802.Google Scholar
Kriz, S. and Harmanec, P.: 1975, Bull. Astron. Inst. Czech. 26, 65.Google Scholar
Lesh, J. R.: 1968, Astrophys. J. Suppl. 17, 371.Google Scholar
Limber, D. N.: 1970, in Slettebak, A. (ed.), Stellar Rotation , D. Reidel Publ. Corp., Dordrecht-Holland, p. 274.Google Scholar
Limber, D. N. and Marlborough, J. M.: 1968, Astrophys. J. 152, 181.CrossRefGoogle Scholar
Peters, G. J.: 1972, Publ. Astron. Soc. Pacific 84, 334.CrossRefGoogle Scholar
Peters, G. J.: 1974, Bull. Am. Astron. Soc. 6, 456.Google Scholar
Peters, G. J.: 1976, in preparation.Google Scholar
Peters, G. J. and Polidan, R. S.: 1973, in Batten, A. H. (ed.), ‘Extended Atmospheres and Circumstellar Matter in Spectroscopic Binary Systems’, IAU Symp. 51, p. 174.Google Scholar
Peters, G. J. and Polidan, R. S.: 1975, IAU Circ. No. 2814.Google Scholar
Plavec, M.: 1970, Publ. Astron. Soc. Pacific 82, 957.CrossRefGoogle Scholar
Plavec, M.: 1973, in Batten, A. H. (ed.), ‘Extended Atmospheres and Circumstellar Matter in Spectroscopic Binary Systems’, IAU Symp. 51, p. 216.Google Scholar
Sackmann, I. J. and Anand, S. P. S.: 1970, Astrophys. J. 162, 105.Google Scholar
Schild, R.: 1973, Astrophys. J. 179, 221.CrossRefGoogle Scholar
Schild, R., Chaffee, F., Frogel, J. A., and Persson, S. E.: 1974, Astrophys. J. 190, 73 Google Scholar
Slettebak, A.: 1952, Astrophys. J. 115, 573.Google Scholar
Uesugi, A. and Fukuda, I.: 1970, Contrib. Inst. Astrophys. Kwasan Obs. Univ. Kyoto , No. 189.Google Scholar
Vidal, C. R., Cooper, J., and Smith, E. W.: 1973, Astrophys. J. Suppl. 25, 37.Google Scholar