EDP Sciences
Free access
Volume 373, Number 2, July II 2001
Page(s) 674 - 682
Section Stellar atmospheres
DOI http://dx.doi.org/10.1051/0004-6361:20010612

A&A 373, 674-682 (2001)
DOI: 10.1051/0004-6361:20010612

FUSE observations of hot white dwarfs

B. Wolff1, J. W. Kruk2, D. Koester1, N. F. Allard3, 4, R. Ferlet3 and A. Vidal-Madjar3

1  Institut für Theoretische Physik und Astrophysik, Universität Kiel, 24098 Kiel, Germany
    e-mail: wolff, koester@astrophysik.uni-kiel.de
2  Center for Astrophysical Sciences, The Johns Hopkins University, Baltimore, MD, 21218, USA
    e-mail: kruk@pha.jhu.edu
3  CNRS Institut d'Astrophysique de Paris, 98bis boulevard Arago, 75014 Paris, France
    e-mail: allard, ferlet, alfred@iap.fr
4  Observatoire de Paris-Meudon, Département Atomes et Molécules en Astrophysique, 92195 Meudon Principal Cedex, France

(Received 6 April 2001 / Accepted 26 April 2001 )

We have analyzed FUSE observations of six hot white dwarf stars: four DA white dwarfs with $T_{\rm eff} \ga 45 000$ K, the DAO Feige 55 ( $T_{\rm eff} \approx 55 000$ K), and the DA CD $-38^{\circ}$ 10980 ( $T_{\rm eff} \approx 24 000$ K). Photospheric lines from Si IV, P V, and S VI can be observed in the majority of the five hotter objects. Feige 55 shows also several other heavier elements. The measured abundances agree only partly with the predictions of the radiative levitation theory. We attribute this to current limitations of the models and the probable presence of mass loss. In the spectrum of CD $-38^{\circ}$ 10980, we have observed the quasi-molecular satellites of L$\beta$. This confirms theoretical predictions about the visibility range for these features.

Key words: stars: abundances -- stars: atmospheres -- white dwarfs -- ultraviolet: stars

Offprint request: B. Wolff, wolff@astrophysik.uni-kiel.de

SIMBAD Objects

© ESO 2001