Hostname: page-component-848d4c4894-ndmmz Total loading time: 0 Render date: 2024-05-10T03:32:51.977Z Has data issue: false hasContentIssue false

Hipparcos Positions of B/Be Stars on the HR Diagram

Published online by Cambridge University Press:  12 April 2016

Danielle Briot
Affiliation:
DASGAL/UMR 8633, Observatoire deParis-Meudon
Noel Robichon
Affiliation:
DASGAL/UMR 8633, Observatoire deParis-Meudon

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.

Absolute magnitudes of Be and B stars are computed for each spectral type and luminosity class V and IV, using the Hipparcos parallax measurements. Some simulations have been carried out in order to estimate the effects which could bias the mean absolute magnitude calculations. As a result, only stars with σπ/π < 15% have been used. A first result is that B stars are fainter than previous estimations by about 0.5 magnitude on average. We then observe that on average Be stars are brighter than B stars of the same spectral type and this over-luminosity increases with the spectral type. A possible interpretation is proposed based on the fact that the rotational velocity of the late Be stars is near the critical rotational velocity.

Type
2. New Missions
Copyright
Copyright © Astronomical Society of the Pacific 2000

References

Arenou, F., Grenon, M., Gomez, A., 1992, A&A, 258, 104 Google Scholar
Arenou, F., Luri, X., 1999, in Harmonizing cosmic distance scales in a post-Hipparcos era, ed. Egret, D. & Heck, A., ASP conf. Series 167, p.13 Google Scholar
Briot, D., 1986, A&A, 163, 67 Google Scholar
Briot, D., Hubert, A.M., Vakili, F., Floquet, M., Hubert, H., 1995, in Future Possibilities for Astrometry in Space, ESA SP-379, p.87 Google Scholar
Briot, D., Robichon, N., Hubert, A.M., 1997, in Hipparcos Venice’97, ESA-SP 402, p.319 Google Scholar
Burki, G., Maeder, A. 1977, A&A, 57, 405 Google Scholar
Collins, G.W., Smith, R.C., 1985, MNRAS, 213, 519 Google Scholar
Collins, G.W., Truax, R.J., Cranmer, S.R., 1991, ApJS, 77, 541 Google Scholar
Endal, A.S., Sofia, S., 1979, ApJ, 232, 531 Google Scholar
ESA, 1997, The Hipparcos and Tycho Catalogues, SP-1200Google Scholar
Houk, N., Smith-Moore, A., 1988, Michigan catalogue of Two-Dimensional spectral types for the HD stars, Vol. 4: -26 to -12 degrees, Univ Michigan Google Scholar
Jaschek, M., Egret, D., 1982, Catalogue of Stellar Groups, SP.Publ. CDS 4, Obs. StrasbourgCrossRefGoogle Scholar
Lutz, T.E., Kelker, D.H., 1973, PASP, 85, 573 Google Scholar
Malmquist, K.G., 1936, Meddel. Stockholm Obs. 26 Google Scholar
Merrill, P.W., 1933, PASP, 45, 198 Google Scholar
Perryman, M.A.C., Lindegren, L., Turon, C., 1997, in Hipparcos Venice’97, ESA SP-402, p.743 Google Scholar
Schmidt-Kaler, Th., 1982, Landolt-Börntein, , New series, group VI, Vol. 2, Sub- Vol. b, p.17 Google Scholar
Slettebak, A., 1979, Space Sci.Rev., 23, 541 Google Scholar
Slettebak, A., 1982, ApJS, 50, 55 Google Scholar
Zorec, J., Briot, D., 1991, A&A, 245, 150 Google Scholar
Zorec, J., Divan, L., Mochkovitch, R., Garcia, A., 1987, IAU Coll. 92, p.68 Google Scholar