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Related papers: White dwarf cooling and large extra dimensions

200 papers

We present the results of our survey searching for new white dwarf pulsators for observations by the TESS space telescope. We collected photometric time-series data on 14 white dwarf variable-candidates at Konkoly Observatory, and found two…

Solar and Stellar Astrophysics · Physics 2018-07-04 Zs. Bognár , Cs. Kalup , Á. Sódor , S. Charpinet , J. J. Hermes

In order to understand the periodic and semi-periodic variations of luminous O- B- A-type stars, linear nonadiabatic stability analyses for radial and nonradial oscillations have been performed for massive evolutionary models ($8M_\odot -…

Solar and Stellar Astrophysics · Physics 2015-05-20 Hideyuki Saio

We present the last HST/STIS E140M FUV spectrum (1150-1725A) of the dwarf nova (DN) WZ Sge, obtained in July 2004, 3 years following the early superoutburst of July 2001. Single white dwarf (WD) synthetic spectral fits (log{g}=8.5) to the…

Astrophysics · Physics 2009-11-11 P. Godon , E. M. Sion , F. Cheng , K. S. Long , B. T. Gaensicke , P. Szkody

Hot white dwarfs with carbon-dominated atmospheres (hot DQs) are a cryptic class of white dwarfs. In addition to their deficiency of hydrogen and helium, most of these stars are highly magnetic, and a large fraction vary in luminosity. This…

Solar and Stellar Astrophysics · Physics 2016-01-21 Kurtis A. Williams , M. H. Montgomery , D. E. Winget , Ross E. Falcon , Michael Bierwagon

Optical spectroscopic observations of white dwarf stars selected from catalogs based on the Gaia DR2 database reveal nine new gaseous debris disks that orbit single white dwarf stars, about a factor of two increase over the previously known…

Solar and Stellar Astrophysics · Physics 2020-12-23 Carl Melis , B. Klein , A. E. Doyle , A. J. Weinberger , B. Zuckerman , P. Dufour

We present a first analysis of the g-mode oscillation spectrum for the white dwarf (WD) primary of GW Lib, a faint cataclysmic variable (CV). Stable periodicities have been observed from this WD for a number of years, but their…

Astrophysics · Physics 2009-11-10 Dean M. Townsley , Phil Arras , Lars Bildsten

The recent discoveries of WD J091405.30+191412.25 (WD J0914 hereafter), a white dwarf likely accreting material from an ice giant planet, and WD 1856+534 b (WD 1856 b hereafter), a Jupiter-sized planet transiting a white dwarf, are the…

Earth and Planetary Astrophysics · Physics 2021-11-24 Alexander P. Stephan , Smadar Naoz , B. Scott Gaudi

Asteroseismology of DAV stars (ZZ Ceti variables) can provide valuable clues about the origin, structure and evolution of DA (atmospheres rich in H) white dwarfs. Recently, a new DAV star, WD J191643.83+393849.7, has been discovered in the…

Solar and Stellar Astrophysics · Physics 2020-10-27 Alejandro H. Córsico , Alejandra D. Romero , Leandro G. Althaus , Marcelo M. Miller Bertolami

We determine projected rotation velocities v sini in DAZ white dwarfs, for the first time using the rotational broadening of the CaII K line. The results confirm previous findings that white dwarfs are very slow rotators, and set even more…

Astrophysics · Physics 2009-11-11 L. Berger , D. Koester , R. Napiwotzki , I. N. Reid , B. Zuckerman

We report the discovery of the first identified pulsating DA white dwarf in the field of the Kepler mission, WD J1916+3938 (Kepler ID 4552982). This ZZ Ceti star was first identified through ground-based, time-series photometry, and…

We present new cooling models for carbon-oxygen white dwarfs with both H- and He-atmospheres, covering the whole relevant mass range, to extend our updated BaSTI (a Bag of Stellar Tracks and Isochrones) stellar evolution archive. They have…

Solar and Stellar Astrophysics · Physics 2021-12-22 Maurizio Salaris , Santi Cassisi , Adriano Pietrinferni , Sebastian Hidalgo

We present atmospheric parameters for a large sample of DA white dwarfs that are known to be photometrically constant. For each star, we determine the effective temperature and surface gravity by comparing high signal-to-noise ratio optical…

Astrophysics · Physics 2009-11-13 A. Gianninas , P. Bergeron , G. Fontaine

ZTF J153932.16+502738.8 (ZTFJ1539) is an eclipsing double-white-dwarf system with an orbital period of 6.91 minutes, and is a significant source of LISA detecting gravitational wave. However, the massive white dwarf (WD) with mass of about…

Solar and Stellar Astrophysics · Physics 2020-02-26 Guoliang Lü , Chunhua Zhu , Zhaojun Wang , Helei Liu , Lin Li , Dian Xie , Jinzhong Liu

White dwarfs are stellar embers depleted of nuclear energy sources that cool over billions of years. These stars, which are supported by electron degeneracy pressure, reach densities of 1e7 grams per cubic centimetre in their cores. It has…

Since the large amplitude 2007 outburst which heated its accreting, pulsating white dwarf, the dwarf nova system GW Librae has been cooling to its quiescent temperature. Our Hubble Space Telescope ultraviolet spectra combined with…

We present new FUV observations of the pulsating DA white dwarf G226-29 obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). This ZZ Ceti star is the brightest one of its class and the coolest white dwarf observed by FUSE. We…

Astrophysics · Physics 2009-11-10 N. F. Allard , G. Hébrard , J. Dupuis , P. Chayer , J. W. Kruk , J. Kielkopf , I. Hubeny

All single stars that are born with masses up to 8.5 - 10 $M_\odot$ will end their lives as a white dwarf (WD) star. In this evolutionary stage, WDs enter the cooling sequence, where the stars radiate away their thermal energy, and are…

Solar and Stellar Astrophysics · Physics 2023-05-10 Weston Hall , Barbara G. Castanheira , Agnès Bischoff-Kim

We present new white dwarf cooling models which incorporate an accurate outer boundary condition based on new opacity and detailed radiative transfer calculations. We find that helium atmosphere dwarfs cool considerably faster than has…

Astrophysics · Physics 2011-02-11 Brad M. S. Hansen

In our galaxy, white dwarfs inevitably undergo scattering and capture processes with the interstellar diffuse dark matter. The captured dark matter forms a dark halo that eventually evaporates or annihilates. Theoretical pulsation modes and…

High Energy Astrophysical Phenomena · Physics 2025-04-10 Bo Zhang , Cui-Bai Luo , Lei Feng

White dwarfs are the end-product of the lifes of intermediate- and low-mass stars and their evolution is described as a simple cooling process. Recently, it has been possible to determine with an unprecedented precision their luminosity…

Astrophysics · Physics 2009-11-13 J. Isern , E. Garcia-Berro , S. Torres , S. Catalan
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