Results 11 to 20 of about 74,403 (250)

NEW PULSATING DB WHITE DWARF STARS FROM THE SLOAN DIGITAL SKY SURVEY [PDF]

The Astrophysical Journal, 2008
We are searching for new He atmosphere white dwarf pulsators (DBVs) based on the newly found white dwarf stars from the spectra obtained by the Sloan Digital Sky Survey. DBVs pulsate at hotter temperature ranges than their better known cousins, the H atmosphere white dwarf pulsators (DAVs or ZZ Ceti stars).
Nitta, Atsuko, Kleinman, S. J., Krzesinski, J., Kepler, S. O., Metcalfe, T. S., Mukadam, Anjum S., Mullally, Fergal, Nather, R. E., Sullivan, Denis J., Thompson, Susan E., Winget, D. E.   +10 more
openaire   +4 more sources

A GRAVITATIONAL REDSHIFT DETERMINATION OF THE MEAN MASS OF WHITE DWARFS: DBA AND DB STARS [PDF]

The Astrophysical Journal, 2012
We measure apparent velocities (v_app) of absorption lines for 36 white dwarfs (WDs) with helium-dominated atmospheres -- 16 DBAs and 20 DBs -- using optical spectra taken for the European Southern Observatory SN Ia progenitor survey (SPY). We find a difference of 6.9+/-6.9 km/s in the average apparent velocity of the H-alpha lines versus that of the ...
Falcon, Ross E., Winget, D. E., Montgomery, Michael H., Williams, Kurtis A.   +3 more
openaire   +4 more sources

Stark Broadening and White Dwarfs [PDF]

Open Astronomy, 2011
White dwarf and pre-white dwarfs are the best types of stars for the application of Stark broadening research results in astrophysics, since in the atmospheres of these stars physical conditions are very favorable for this line broadening mechanism - in ...
Dimitrijević Milan S., Kovačević Andjelka, Simić Zoran, Sahal-Bréchot Sylvie   +3 more
doaj   +4 more sources

Doppler beaming factors for white dwarfs, main sequence stars, and giant stars [PDF]

Astronomy & Astrophysics, 2020
Context. Systematic theoretical calculations of Doppler beaming factors are scarce in the literature, particularly in the case of white dwarfs. Additionally, there are no specific calculations for the limb-darkening coefficients of 3D white dwarf models. Aims.
Claret, A., Cukanovaite, E., Burdge, K., Tremblay, P.-E., Parsons, S., Marsh, T.R.   +5 more
openaire   +6 more sources

A White Dwarf Search Model Based on a Deep Transfer-learning Method

The Astrophysical Journal Supplement Series, 2023
White dwarfs represent the ultimate stage of evolution for over 97% of stars and play a crucial role in studies of the Milky Way’s structure and evolution.
Lei Tan, Zhicun Liu, Feng Wang, Ying Mei, Hui Deng, Chao Liu   +5 more
doaj   +1 more source

STAR load balancing and tiered-storage infrastructure strategy for ultimate db access [PDF]

Journal of Physics: Conference Series, 2011
In recent years, the STAR experiment's database demands have grown in accord not only with simple facility growth, but also with a growing physics program. In addition to the accumulated metadata from a decade of operations, refinements to detector calibrations force user analysis to access database information post data production.
D Arkhipkin, J Lauret, W Betts, L Didenko, G Van Buren   +4 more
openaire   +1 more source

A search for a new class of pulsating DA white dwarf stars in the DB gap [PDF]

Monthly Notices of the Royal Astronomical Society, 2008
While white dwarf stars are classified into many subgroups based on the appearance of hydrogen, helium, carbon, oxygen and other spectral lines – or even pure continuum with no lines in the case of the DC stars – the vast majority fall into two major subgroups: those with hydrogen atmospheres (the DA white dwarfs), and those with helium atmospheres ...
D. W. Kurtz, H. Shibahashi, V. S. Dhillon, T. R. Marsh, S. P. Littlefair   +4 more
openaire   +4 more sources

A Comprehensive Spectroscopic Analysis of DB White Dwarfs [PDF]

, 2011
We present a detailed analysis of 108 helium-line (DB) white dwarfs based on model atmosphere fits to high signal-to-noise optical spectroscopy. We derive a mean mass of 0.67 Mo for our sample, with a dispersion of only 0.09 Mo. White dwarfs also showing
A. Beauchamp, A. Gianninas, Beauchamp, Beauchamp, Beauchamp, Beauchamp, Beauchamp, Beauchamp, Bergeron, Bergeron, Brassard, Brassard, Böhm, C. Hunter, Deridder, Desharnais, Dufour, Dufour, Dufour, Dufour, Eisenstein, F. Wesemael, Fontaine, Friedrich, G. Fontaine, Gould, Holberg, Holberg, Holberg, Hunter, James Liebert, John, Koester, Liebert, Limoges, Limoges, Lépine, M. T. Ruiz, M.-M. Limoges, Massa, P. Bergeron, Patrick Dufour, Petitclerc, Pierre Dufour, Press, Rex A. Saffer, Tremblay, Tremblay, Tremblay, van Altena, Wesemael, Wickramasinghe   +51 more
core   +1 more source

Analysis of IUE spectra of helium-rich white dwarf stars [PDF]

, 2006
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 model atmospheres, we simultaneously determine spectroscopic distances ...
Althaus, Althaus, B. G. Castanheira, Beauchamp, Bergeron, Bergeron, Corsico, D. Koester, Finley, G. Handler, Hansen, Holberg, Kepler, Kjeldsen, Metcalfe, Metcalfe, Montgomery, O'Donoghue, Provencal, Robinson, S. O. Kepler, Winget, Winget, Wolff   +23 more
core   +2 more sources

The potential for asteroseismology of DB white dwarf stars

The Astrophysical Journal, 1993
We present the results of a parametric survey of evolutionary models of compositionally stratified white dwarfs with helium surface layers (DB white dwarfs). Because white dwarfs are the most common final end state of stellar evolution, determining their internal structure will offer us many clues about stellar evolution and the physics of matter under
P. A. Bradley, D. E. Winget, M. A. Wood
openaire   +1 more source