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White dwarf mass distribution in the SDSS
We determined masses for the 7167 DA and 507 DB white dwarf stars classified as single and non-magnetic in Data Release 4 of the Sloan Digital Sky Survey (SDSS). We obtained revised T eff and log gExpand
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A new class of pulsating white dwarf of extremely low mass: The fourth and fifth members
We report the discovery of two new pulsating extremely low-mass (ELM) white dwarfs (WDs), SDSS J161431.28+191219.4 (hereafter J1614) and SDSS J222859.93+362359.6 (hereafter J2228). Both WDs haveExpand
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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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Seismological studies of ZZ Ceti stars – II. Application to the ZZ Ceti class
We used the detected pulsation modes and adiabatic pulsation models to do seismology of the class of ZZ Ceti stars and measure the H layer mass for 83 stars. We found the surface hydrogen layer to beExpand
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Seismological studies of ZZ Ceti stars -I. The model grid and the application to individual stars
We calculate and explore an extensive adiabatic model grid for pulsating white dwarfs with hydrogen-dominated atmospheres, the ZZ Ceti stars. We also compared the computed modes with the observedExpand
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Discovery of an ultramassive pulsating white dwarf
We announce the discovery of the most massive pulsating hydrogen-atmosphere (DA) white dwarf (WD) ever discovered, GD 518. Model atmosphere fits to the optical spectrum of this star show it is aExpand
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Analysis of IUE spectra of helium-rich white dwarf stars
We studied the class of DB white dwarf stars, using re-calibrated UV spectra for thirty four DBs obtained with the IUE satellite. By comparing the observed energy distributions with modelExpand
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Two New Long-Period Giant Planets from the McDonald Observatory Planet Search and Two Stars with Long-Period Radial Velocity Signals Related to Stellar Activity Cycles
We report the detection of two new long-period giant planets orbiting the stars HD 95872 and HD 162004 (psi1 Draconis B) by the McDonald Observatory planet search. The planet HD 95872b has a minimumExpand
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Discovery of eleven new ZZ Ceti stars
We report the discovery of eleven new ZZ Cetis using telescopes at OPD (Observatorio do Pico dos Dias/LNA) in Brazil, the 4.1 m SOAR (Southern Astrophysical Research) telescope at Cerro Pachon,Expand
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Discovery of five new massive pulsating white dwarf stars
Using the SOuthern Astrophysical Research telescope (SOAR) Optical Imager at the SOAR 4.1 m telescope, we report on the discovery of five new massive pulsating white dwarf stars. Our resultsExpand
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