Results 31 to 40 of about 84,708 (345)

Stellar equilibrium configurations of white dwarfs in the f(R, T) gravity

open access: yesEuropean Physical Journal C: Particles and Fields, 2017
In this work we investigate the equilibrium configurations of white dwarfs in a modified gravity theory, namely, f(R, T) gravity, for which R and T stand for the Ricci scalar and trace of the energy-momentum tensor, respectively.
G. A. Carvalho   +6 more
doaj   +1 more source

Disk or Companion: Characterizing Excess Infrared Flux in Seven White Dwarf Systems with Near-infrared Spectroscopy

open access: yesThe Astronomical Journal, 2023
Excess infrared flux from white dwarf stars is likely to arise from a dusty debris disk or a cool companion. In this work, we present near-infrared spectroscopic observations with Keck/MOSFIRE, Gemini/GNIRS, and Gemini/Flamingos-2 of seven white dwarfs ...
Dylan Owens   +9 more
doaj   +1 more source

The DB gap and a new class of pulsating white dwarfs

open access: yesEPJ 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

A population synthesis study of the luminosity function of hot white dwarfs

open access: yes, 2014
We present a coherent and detailed Monte Carlo simulation of the population of hot white dwarfs. We assess the statistical significance of the hot end of the white dwarf luminosity function and the role played by the bolometric corrections of hydrogen ...
García-Berro, E.   +3 more
core   +1 more source

White dwarfs and Galactic dark matter [PDF]

open access: yes, 2002
We discuss the recent discovery by Oppenheimer et al (2001) of old, cool white dwarf stars, which may be the first direct detection of Galactic halo dark matter.
Flynn, Chris   +2 more
core   +3 more sources

A Systematic Study of the Connection Between White Dwarf Period Spectra and Model Structure

open access: yesThe Astrophysical Journal, 2023
To date, pulsational variability has been measured for nearly 70 pulsating helium-atmosphere white dwarfs (DBVs) and 500 pulsating hydrogen-atmosphere white dwarfs (DAVs), with only a fraction of these having been the subject of asteroseismic analysis ...
Agnès Bischoff-Kim
doaj   +1 more source

The True Incidence of Magnetism among Field White Dwarfs [PDF]

open access: yes, 2002
We study the incidence of magnetism in white dwarfs from three large and well-observed samples of hot, cool, and nearby white dwarfs in order to test whether the fraction of magnetic degenerates is biased, and whether it varies with effective temperature,
Dreizler S.   +7 more
core   +4 more sources

White dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 14 [PDF]

open access: yes, 2019
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 insight into the early ages of each population.
Amaral, Larissa A.   +8 more
core   +2 more sources

Effects of modified gravity on microscopic properties and cooling timescale of white dwarfs

open access: yesPhysics Letters B
There are currently two open questions in white dwarf physics: why are massive dwarfs observed less often in astronomical surveys, and why have not any super-Chandrasekhar white dwarfs been found despite the discovery of more than a dozen peculiar ...
Aneta Wojnar   +2 more
doaj   +1 more source

Stark Broadening and White Dwarfs

open access: yesOpen 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.   +3 more
doaj   +1 more source

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