Bibcode
DOI
Bergeron, P.; Fontaine, G.; Billères, M.; Boudreault, S.; Green, E. M.
Referencia bibliográfica
The Astrophysical Journal, Volume 600, Issue 1, pp. 404-408.
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1
2004
Revista
Número de citas
140
Número de citas referidas
95
Descripción
We report the discovery of two new ZZ Ceti pulsators, LP 133-144 and HE
1258+0123, selected on the basis of model atmosphere fits to optical
spectroscopic data. The atmospheric parameters for LP 133-144
(Teff=11,800+/-200 K and logg=7.87+/-0.05) and for HE
1258+0123 (Teff=11,410+/-200 K and logg=8.04+/-0.05) place
them within the empirical boundaries of the ZZ Ceti instability strip.
This brings the number of known ZZ Ceti stars to a total of 36, a
quarter of which have now been discovered using the spectroscopic
approach for estimating their atmospheric parameters. This method has
had a 100% success rate so far in predicting the variability of
candidate ZZ Ceti stars. We have also analyzed additional spectra of
known nonvariable white dwarfs in the vicinity of the ZZ Ceti
instability strip. Our study further strengthens the idea that ZZ Ceti
stars occupy a pure region in the logg-Teff plane, a region
where no nonvariable stars are found. This result supports the thesis
that ZZ Ceti pulsators represent a phase through which all DA stars must
evolve.
Based, in part, on observations gathered at the European Southern
Observatory, La Silla, Chile.