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We present a new catalog of spectroscopically confirmed white dwarf stars from the Sloan Digital Sky Survey (SDSS) Data Release 7 spectroscopic catalog. We find 20,407 white dwarf spectra,Expand
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An independent method for determining the age of the universe
An age of 9.3 + or - 2.0 Gyr is derived for the Galactic disk on the basis of comparisons between the sudden drop in the observed luminosity distribution and theoretical evolutionary white dwarfExpand
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New white dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 12
White dwarfs carry information on the structure and evolution of the Galaxy, especially through their luminosity function and initial-to-final mass relation. Very cool white dwarfs provide insightExpand
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New white dwarf stars in the Sloan Digital Sky Survey Data Release 10
We report the discovery of 9 089 new spectroscopically confirmed white dwarfs and subdwarfs in the Sloan Digital Sky Survey Data Release 10. We obtain Teff, log g and mass for hydrogen atmosphereExpand
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Asteroseismology of the DOV star PG 1159 - 035 with the Whole Earth Telescope
Results are reported from 264.1 hr of nearly continuous time-series photometry on the pulsating prewhite dwarf star (DPV) PG 1159 - 035. The power spectrum of the data set is completely resolved intoExpand
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Toward ensemble asteroseismology of ZZ Ceti stars with fully evolutionary models
ZZ Ceti stars form the most numerous group of degenerate variable stars. They are otherwise normal DA (H-rich atmospheres) white dwarfs that exhibit pulsations. Here, we present anExpand
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DB white dwarfs in the Sloan Digital Sky Survey Data Release 10 and 12
White dwarfs with helium-dominated atmospheres comprise approximately 20% of all white dwarfs. Among the open questions are the total masses and the origin of the hydrogen traces observed in a largeExpand
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Magnetic white dwarf stars in the Sloan Digital Sky Survey
To obtain better statistics on the occurrence of magnetism among white dwarfs, we searched the spectra of the hydrogen atmosphere white dwarf stars (DAs) in the Data Release 7 of the Sloan DigitalExpand
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Limits on planets around pulsating white dwarf stars
We present limits on planetary companions to pulsating white dwarf stars. A subset of these stars exhibit extreme stability in the period and phase of some of their pulsation modes; a planet can beExpand
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Thirty-Five New Pulsating Da White Dwarf Stars
We present 35 new pulsating DA (hydrogen atmosphere) white dwarf stars discovered from the Sloan Digital Sky Survey (SDSS) and the Hamburg Quasar Survey (HQS). We have acquired high-speed time seriesExpand
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