Results 21 to 30 of about 5,483 (223)
Seismic Cartography of White-Dwarf Interiors From the Toulouse-Montréal Optimal-Design Approach
Frontiers in Astronomy and Space Sciences, 2022 Probing internal properties of white-dwarf stars has been amongst the earliest objectives of asteroseismology, following the first discovery in the late 1960s of non-radial pulsations in these evolved compact stars.
Noemi Giammichele +2 more
doaj +1 more source
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. +5 more
openaire +6 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. +3 more
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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 +5 more
doaj +1 more source
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
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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 +10 more
openaire +3 more sources
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 +4 more
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The Astrophysical Journal, 2022 Abstract We continue our comprehensive theoretical investigation of the spectral evolution of white dwarfs based on sophisticated simulations of element transport. In this paper, we focus on the transformation of PG 1159 stars into DO/DB white dwarfs due to the gravitational settling of heavy elements and then into DQ white dwarfs ...
A. Bédard, P. Bergeron, P. Brassard
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The DB gap and a new class of pulsating white dwarfs
EPJ Web of Conferences, 2013 The recent systematic surveys providing enormously massive datasets of white dwarfs show that there is still a deficit of a factor of 2.5 in the DA/non-DA ratio within the temperature range of 30 000 K < Teff < 45 000 K, which has been regarded as the ...
Shibahashi H.
doaj +1 more source
The Astrophysical Journal, 1999 We have secured optical spectra for the eight currently known variable DB, or V777 Her, stars. With the help of a new generation of synthetic spectra, spectroscopic effective temperatures are derived for these objects, as well as for 15 other DB or DBA stars above 20,000 K.
A. Beauchamp +6 more
openaire +1 more source