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Related papers: White dwarf constraints on a varying $G$

200 papers

The formation channels and predicted populations of double-white dwarfs (DWDs) are important because a subset will evolve to be gravitational-wave sources and/or progenitors of Type Ia supernovae. Given the observed population of…

Solar and Stellar Astrophysics · Physics 2020-07-22 E. C. Wilson , J. Nordhaus

Recent measurements made by Hipparcos (Provencal et al. 1998) present observational evidence supporting the existence of some white dwarf (WD) stars with iron - rich, core composition. In this connection, the present paper is aimed at…

Astrophysics · Physics 2009-10-31 J. A. Panei , L. G. Althaus , O. G. Benvenuto

We have extended our detailed survey of the local white dwarf population from 20 pc to 25 pc, effectively doubling the sample volume, which now includes 232 stars. In the process new stars within 20 pc have been added, a more uniform set of…

Solar and Stellar Astrophysics · Physics 2016-06-06 J. B. Holberg T. D. Oswalt , E. M. Sion , G. P. McCook

We explore changes in the adiabatic low-order g-mode pulsation periods of 0.526, 0.560, and 0.729 M$_\odot$ carbon-oxygen white dwarf models with helium-dominated envelopes due to the presence, absence, and enhancement of $^{22}$Ne in the…

We present a census of photometrically detected rotation periods for white dwarf (WD) stars. We analyzed the light curves of 9285 WD stars observed by the Transiting Exoplanet Survey Satellite up to Sector 69. Using Fourier transform…

Solar and Stellar Astrophysics · Physics 2025-01-09 Gabriela Oliveira da Rosa , S. O. Kepler , L. T. T. Soethe , Alejandra D. Romero , Keaton J. Bell

Magnetic cataclysmic variables are close binaries which consist of a compact object - a white dwarf - and a red dwarf filling its Roche Lobe. Such systems are physical laboratories which enable study of the influence of magnetic fields on…

Solar and Stellar Astrophysics · Physics 2019-08-14 V. Breus , K. Petrik , S. Zola

I demonstrate that an effect similar to the Roemer delay, familiar from timing radio pulsars, should be detectable in the first eclipsing double white dwarf (WD) binary, NLTT 11748. By measuring the difference of the time between the…

Astrophysics of Galaxies · Physics 2015-05-19 David L Kaplan

The formation of globular clusters remains an open debate. Dwarf starburst galaxies are efficient at forming young massive clusters with similar masses as globular clusters and may hold the key to understanding their formation. We study…

Double white dwarf (DWD) binaries are natural outcomes of binary stellar evolution and key sources for future space-based gravitational wave (GW) observatories such as Laser Interferometer Space Antenna (LISA). We investigate how different…

Solar and Stellar Astrophysics · Physics 2026-04-24 Sreeta Roy , Surajit Kalita

We model the dynamics of test binaries in isotropic, multi-mass models of galactic globular clusters. The evolution of binary orbits through the cluster potentials is modeled, including second order diffusion terms, and probabilities for…

Astrophysics · Physics 2008-11-26 Steinn Sigurdsson , E. S. Phinney

Theories with varying gravitational constant $G$ have been studied since long time ago. Among them, the most promising candidates as alternatives of the standard General Relativity are known as scalar-tensor theories. They provide…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Diego F. Torres

Pulsars in close binary orbit around another neutron star or a massive white dwarf make ideal laboratories for testing the predictions of gravitational radiation and self-gravitational effects. We report new timing measurements of the…

Astrophysics · Physics 2008-11-26 N. D. Ramesh Bhat , Matthew Bailes , Joris P. W. Verbiest

This is the second in a series of papers associated with cataclysmic variables (CVs) and related objects, formed in a suite of simulations for globular cluster evolution performed with the MOCCA Monte Carlo code. We study the properties of…

Astrophysics of Galaxies · Physics 2016-12-05 Diogo Belloni , Mirek Giersz , Helio J. Rocha-Pinto , Nathan Leigh , Abbas Askar

White dwarfs are the most common endpoints of stellar evolution. They are often found in close binary systems in which the white dwarf is accreting matter from a companion star, either via an accretion disc or channelled along the white…

Solar and Stellar Astrophysics · Physics 2023-03-20 Natalie A. Webb

We have examined the radial distribution of white dwarfs over a single HST/ACS field in the nearby globular cluster NGC 6397. In relaxed populations, such as in a globular cluster, stellar velocity dispersion, and hence radial distribution,…

New results based on methods of population synthesis, concerning magnetic field effects on the evolution of pulsars are reported. The present study confirms that models with timescales for the magnetic field decay longer than the pulsar…

Astrophysics · Physics 2009-11-06 T. Regimbau , J. A. de Freitas Pacheco

We investigate the formation of the ten double-lined double white dwarfs that have been observed so far. A detailed stellar evolution code is used to calculate grids of single-star and binary models and we use these to reconstruct possible…

Astrophysics · Physics 2007-05-23 M. V. van der Sluys , F. Verbunt , O. R. Pols

Element diffusion is a key physical process that substantially impacts the superficial abundances, internal structure, pulsation properties, and evolution of white dwarfs. We study the effect of Coulomb separation of ions in the cooling…

Solar and Stellar Astrophysics · Physics 2021-01-04 Leandro G. Althaus , Alejandro H. Córsico , Francisco De Gerónimo

We present in this work new pulsational calculations for improved carbon-oxygen DA white dwarf models suitable for the study of massive ZZ Ceti stars. The background models employed in this study, presented in detail in a recent paper by…

Astrophysics · Physics 2009-11-10 A. H. Corsico , L. G. Althaus , M. H. Montgomery , E. Garcia-Berro , J. Isern

Cool white dwarfs are reliable and independent stellar chronometers. The most common white dwarfs have carbon-oxygen dense cores. Consequently, the cooling ages of very cool white dwarfs sensitively depend on the adopted phase diagram of…

Solar and Stellar Astrophysics · Physics 2015-05-30 Leandro G. Althaus , Enrique García-Berro , Jordi Isern , Alejandro H. Córsico , Marcelo M. Miller Bertolami