FUSE observations of PG1342+444

New insights into the nature of the hottest DA white dwarfs

M. A. Barstow, S. A. Good, J. B. Holberg, M. R. Burleigh, N. P. Bannister, Ivan - Hubeny, R. Napiwotzki

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

We present Far Ultraviolet Spectroscopic Explorer (FUSE) observations of the very hot (Teff ≈ 60 000 K) DA white dwarf PG1342+444, describing our data reduction and analysis techniques. The spectrum reveals a number of photospheric absorption lines from high ionization species along with numerous interstellar features. The photospheric detections include the 1031.9- and 1037.0-Å O VI lines which are seen for the first time in a hot DA atmosphere and are usually associated with the much hotter PG1159 stars and so-called O VI central stars of planetary nebulae. Estimates of the stellar effective temperature made independently using both the Balmer and Lyman series lines are in disagreement (Teff ≈ 67 000 and ≈54 000 K respectively), when taking into account just the statistical uncertainties in the analyses. However, the presence of weak absorption from the C III multiplet near 1176 Å, which is predicted to be much stronger if the star were as cool as the Lyman measurement suggests, leads us to favour the higher temperature. PG1342+444 appears to have enhanced C, Fe and Ni abundances in its atmosphere compared with all the other G191 -B2B-like DA white dwarfs, which might affect the temperature structure of the atmosphere if not homogeneously distributed, as assumed in this study.

Original languageEnglish (US)
Pages (from-to)425-434
Number of pages10
JournalMonthly Notices of the Royal Astronomical Society
Volume330
Issue number2
DOIs
StatePublished - Feb 21 2002
Externally publishedYes

Fingerprint

atmospheres
atmosphere
Balmer series
stars
hot stars
data reduction
planetary nebulae
ionization
temperature
fine structure
estimates
detection
analysis

Keywords

  • Methods: data analysis
  • Stars: abundances
  • Stars: atmospheres
  • Stars: individual: PG1342+444
  • Ultraviolet: stars
  • White dwarfs

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

FUSE observations of PG1342+444 : New insights into the nature of the hottest DA white dwarfs. / Barstow, M. A.; Good, S. A.; Holberg, J. B.; Burleigh, M. R.; Bannister, N. P.; Hubeny, Ivan -; Napiwotzki, R.

In: Monthly Notices of the Royal Astronomical Society, Vol. 330, No. 2, 21.02.2002, p. 425-434.

Research output: Contribution to journalArticle

Barstow, M. A. ; Good, S. A. ; Holberg, J. B. ; Burleigh, M. R. ; Bannister, N. P. ; Hubeny, Ivan - ; Napiwotzki, R. / FUSE observations of PG1342+444 : New insights into the nature of the hottest DA white dwarfs. In: Monthly Notices of the Royal Astronomical Society. 2002 ; Vol. 330, No. 2. pp. 425-434.
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