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The discovery of Ni V in the photospheres of the hot DA white dwarfs RE 2214-492 and G191-B2BWe have co-added six recently obtained International Ultraviolet Explorer (IUE) echelle spectra of the hot DA white dwarf RE 2214-492 and 10 existing archive spectra of the well-known hot DA, G191-B2B. We find that both stars contain numerous weak features due to Ni V. Nickel is thus the second iron-group element to be found in the spectra of the very hottest DA white dwarfs. In addition to Ni V, we also observe Al III in both stars and present evidence for the possible presence of Ni IV and Fe IV in RE 2214-492. The presence of Ni and Al, together with previously reported elements, will contribute significantly to both the EUV opacity and to the apparent complexity of the UV spectra of these stars. Using Non-Local Thermodynamic Equilibrium (NLTE) model atmospheres we estimate the Ni abundances in RE 2214-492 the G191-B2B to be log(Ni/H) = -5.5 +/- 0.3 and -6.0 +/- 0.3, respectively.
Document ID
19950035655
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Holberg, J. B.
(University of Arizona, Tucson, AZ United States)
Hubeny, I.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Barstow, M. A.
(University of Leicester Leicester, United Kingdom)
Lanz, T.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Sion, E. M.
(Villanova University Villanova, PA, United States)
Tweedy, R. W.
(University of Arizona, Tucson, AZ United States)
Date Acquired
August 16, 2013
Publication Date
April 20, 1994
Publication Information
Publication: Astrophysical Journal, Part 2 - Letters
Volume: 425
Issue: 2
ISSN: 0004-637X
Subject Category
Astronomy
Accession Number
95A67254
Funding Number(s)
CONTRACT_GRANT: NAGW-5434
CONTRACT_GRANT: NAGW-3158
Distribution Limits
Public
Copyright
Other

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