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Related papers: Phase Separation in Ultramassive White Dwarfs

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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 report the detection of 13 heavy elements (Na, Mg, Al, Si, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, and Sr) in the photosphere of LSPM J0207+3331, a ~3 Gyr old hydrogen-rich white dwarf with an effective temperature comparable to that of the Sun.…

We present follow-up spectroscopy of 711 white dwarfs within 100 pc, and present a detailed model atmosphere analysis of the 100 pc white dwarf sample in the SDSS footprint. Our spectroscopic follow-up is complete for 83% of the white…

Solar and Stellar Astrophysics · Physics 2020-08-05 Mukremin Kilic , P. Bergeron , Alekzander Kosakowski , Warren R. Brown , Marcel A. Agueros , Simon Blouin

Nine metal-polluted white dwarfs are observed with medium-resolution optical spectroscopy,where photospheric abundances are determined and interpreted through comparison against solar system objects. An improved method of making such…

Earth and Planetary Astrophysics · Physics 2019-10-09 Andrew Swan , Jay Farihi , Detlev Koester , Mark Hollands , Steven Parsons , P. Wilson Cauley , Seth Redfield , Boris T. Gaensicke

Cooling ages of white dwarfs are routinely determined by mapping effective temperatures and masses to ages using evolutionary models. Typically, the reported uncertainties on cooling ages only consider the error propagation of the…

Solar and Stellar Astrophysics · Physics 2025-03-12 Praneet Pathak , Simon Blouin , Falk Herwig

We show that the merger and tidal disruption of a C/O white dwarf (WD) by a neutron star (NS) binary companion provides a natural formation scenario for the PSR B1257+12 planetary system. Starting with initial conditions for the debris disk…

Earth and Planetary Astrophysics · Physics 2017-01-25 Ben Margalit , Brian D. Metzger

We provide a fine and homogeneous grid of evolutionary sequences for He-core white dwarfs with masses 0.15-0.45 Msun, including the mass range for ELM white dwarfs (<0.20Msun). The grid is appropriate for mass and age determination, and to…

Solar and Stellar Astrophysics · Physics 2015-06-16 Leandro G. Althaus , Marcelo M. Miller Bertolami , Alejandro H. Córsico

A White Dwarf (WD) star and a main-sequence companion may interact through their different stellar evolution stages. This sort of binary population has historically helped us improve our understanding of binary formation and evolution…

High Energy Astrophysical Phenomena · Physics 2019-01-30 Ali Taani

DA-type white dwarfs account for 80% of all white dwarfs and represent, for most of them, the ultimate outcome of the typical evolution of low-to-intermediate mass stars. Their internal chemical stratification is strongly marked by passed,…

Solar and Stellar Astrophysics · Physics 2021-07-09 S. Charpinet , N. Giammichele , P. Brassard , G. Fontaine , P. Bergeron , W. Zong , V. Van Grootel , A. S. Baran

We carried out a spectroscopic investigation of single lined white dwarfs (WDs) in double degenerate (DD) systems and discuss their binary evolution. Simulated spectra of the Halpha region are used to derive upper limits on the temperature…

Solar and Stellar Astrophysics · Physics 2009-07-22 S. Weston , R. Napiwotzki

We investigate the evolution of cooling helium atmosphere white dwarfs using a full evolutionary code, specifically developed for following the effects of element diffusion and gravitational settling on white dwarf cooling. The major…

Astrophysics · Physics 2016-08-16 James MacDonald , Margarita Hernanz , Jordi José

We study ultralight scalar fields with quadratic couplings to Standard-Model fermions and derive strong constraints from white-dwarf mass-radius data. Such couplings source scalar profiles inside compact stars, shift fermion masses, and can…

High Energy Physics - Phenomenology · Physics 2026-05-18 Kai Bartnick , Konstantin Springmann , Stefan Stelzl , Andreas Weiler

We report on first results of computing synthetic spectra from H/He-poor accretion disks in ultracompact LMXBs. We aim at the determination of the chemical composition of the very low-mass donor star, which is the core of a former C/O white…

Astrophysics · Physics 2007-05-23 K. Werner , T. Nagel , S. Dreizler , T. Rauch

The evolution of a star of initial mass 10 $M_{\odot}$, and metallicity $Z = 0.02$ in a Close Binary System (CBS) is followed from its main sequence until an ONe degenerate remnant forms. Restrictions have been made on the characteristics…

Astrophysics · Physics 2009-11-06 P. Gil-Pons , E. Garcia-Berro

Ultracool dwarfs have emerged as key targets for searches of transiting exoplanets. Precise estimates of the host parameters (including mass, age, and radius) are fundamental to constrain the physical properties of orbiting exoplanets. We…

We conduct the first 3D hydrodynamic simulations of oxygen-neon white dwarf-neutron star/black hole mergers (ONe WD-NS/BH mergers). Such mergers constitute a significant fraction, and may even dominate, the inspiral rates of all WD-NS…

High Energy Astrophysical Phenomena · Physics 2024-01-17 Alexey Bobrick , Yossef Zenati , Hagai B. Perets , Melvyn B. Davies , Ross Church

The merger of close double white dwarfs (CDWDs) is one of the favourite evolutionary channels for producing Type Ia supernovae (SN Ia). Unfortunately, current theories of the evolution and formation of CDWDs are still poorly constrained and…

Solar and Stellar Astrophysics · Physics 2017-01-18 A. Rebassa-Mansergas , S. G. Parsons , E. Garcia-Berro , B. T. Gaensicke , M. R. Schreiber , M. Rybicka , D. Koester

Binary stellar evolution calculations predict that Chandrasekhar-mass carbon/oxygen white dwarfs (WDs) show a radially varying profile for the composition with a carbon depleted core. Many recent multi-dimensional simulations of Type Ia…

Solar and Stellar Astrophysics · Physics 2014-12-03 Sebastian T. Ohlmann , Markus Kromer , Michael Fink , Rüdiger Pakmor , Ivo R. Seitenzahl , Stuart A. Sim , Friedrich K. Roepke

There are many candidate sites of the r-process: core-collapse supernovae (including rare magnetorotational core-collapse supernovae), neutron star mergers, and neutron star/black hole mergers. The chemical enrichment of…

Astrophysics of Galaxies · Physics 2018-12-19 Gina E. Duggan , Evan N. Kirby , Serge M. Andrievsky , Sergey A. Korotin

White dwarfs with a F, G or K type companion represent the last common ancestor for a plethora of exotic systems throughout the galaxy, though to this point very few of them have been fully characterised in terms of orbital period and…

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