2010A&A...524A...9W


C.D.S. - SIMBAD4 rel 1.7 - 2019.11.14CET01:05:27

2010A&A...524A...9W - Astronomy and Astrophysics, volume 524, A9-9 (2010/12-1)

Metal abundances in the hottest known DO white dwarf (KPD 0005+5106).

WASSERMANN D., WERNER K., RAUCH T. and KRUK J.W.

Abstract (from CDS):

We present the analysis of ultraviolet and optical spectra of KPD0005+5106. Redetermination of the atmospheric parameters is necessary because the recent discovery of highly ionised metals (NeVIII, CaX) indicates that the effective temperature is significantly higher than previously thought. Here we announce the discovery of lines from highly ionised silicon, sulphur, and iron (SiVII, SVII, FeX) which were never found before in any stellar photosphere. Our analysis of these lines and those from helium and several other metals gives Teff= 200000±20000K, logg=6.7±0.3. Mass and luminosity follow from a comparison with evolutionary tracks: M=0.64M and logL/L=3.7, so that, strictly speaking, the star is a helium-burning pre-white dwarf. The mass fractions of the metals in the helium-dominated atmosphere are in the range 0.7-4.3 solar. Hydrogen is not detectable and we derive an upper abundance limit of 0.034 solar. This abundance pattern is probably unaffected by gravitational settling and radiative levitation. Its origin lies in previous evolutionary stages. We discuss the link of KPD0005+5106 to R CrB stars and the possibility that it results from a double-degenerate merger event.

Abstract Copyright:

Journal keyword(s): stars: abundances - stars: atmospheres - stars: evolution - stars: AGB and post-AGB - white dwarfs - stars: individual: KPD 0005+5106

Simbad objects: 4

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Number of rows : 4

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 KPD 0005+5106 WD* 00 08 18.1706793307 +51 23 16.594540226 11.80 13.04 13.32 13.53   DOZ1 113 0
2 V* GW Vir WD* 12 01 45.9728868858 -03 45 40.627851273   14.87 15.04     DOQZ1 458 0
3 V* Y Mus RC* 13 05 48.1950457380 -65 30 46.622944615   11.3 10.50     Fp_Hd 58 0
4 PG 1501+664 WD* 15 02 09.6296551839 +66 12 19.146114550   16.07 16.37     DZQ1 148 0

    Equat.    Gal    SGal    Ecl

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2019.11.14-01:05:27

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