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Related papers: Carbon-Oxygen Phase Separation in MESA White Dwarf…

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Over the last decade {\it ab initio} modeling of material properties has become widespread in diverse fields of research. It has proved to be a powerful tool for predicting various properties of matter under extreme conditions. We apply…

Solar and Stellar Astrophysics · Physics 2015-05-20 Piotr M. Kowalski , Mukremin Kilic

We investigate the effects of element diffusion on the structure and evolution of low-mass helium white dwarfs (WD). Attention is focused on the occurrence of hydrogen shell flashes induced by diffusion processes during cooling phases.…

Astrophysics · Physics 2009-10-31 L. G. Althaus , A. M. Serenelli , O. G. Benvenuto

The present work is designed to explore the evolution of helium-core white dwarf (HeWD) stars for the case of metallicities much lower than the solar one (Z=0.001 and Z=0.0002). Evolution is followed in a self-consistent way with the…

Astrophysics · Physics 2009-11-07 A. M. Serenelli , L. G. Althaus , R. D. Rohrmann , O. G. Benvenuto

We assess the impact of the trace element ^{22}Ne on the cooling and seismology of a liquid C/O white dwarf (WD). Due to this elements' neutron excess, it sinks towards the interior as the liquid WD cools. The subsequent gravitational…

Astrophysics · Physics 2009-11-07 Christopher J. Deloye , Lars Bildsten

Convective overshooting in super asymptotic giant branch stars has been suggested to lead to the formation of hybrid white dwarfs with carbon-oxygen cores and oxygen-neon mantles. As the white dwarf cools, this core-mantle configuration…

Solar and Stellar Astrophysics · Physics 2019-05-01 Josiah Schwab , Pascale Garaud

We update the capabilities of the software instrument Modules for Experiments in Stellar Astrophysics (MESA) and enhance its ease of use and availability. Our new approach to locating convective boundaries is consistent with the physics of…

White dwarf evolution is essentially a gravothermal cooling process, which,for cool white dwarfs, sensitively depends on the treatment of the outer boundary conditions. We provide detailed outer boundary conditions appropriate for computing…

Solar and Stellar Astrophysics · Physics 2015-06-11 R. D. Rohrmann , L. G. Althaus , E. García-Berro , A. H. Córsico , M. M. Miller Bertolami

We use Modules for Experiments in Stellar Astrophysics (MESA) to construct stellar evolution models that reach a hydrogen-deficient, carbon-rich giant phase like the R Coronae Borealis (R CrB) stars. These models use opacities from OPAL and…

Solar and Stellar Astrophysics · Physics 2019-11-13 Josiah Schwab

We present an empirical determination of the white dwarf cooling sequence in the globular cluster 47 Tucanae. Using spectral models, we determine temperatures for 887 objects from Wide Field Camera 3 data, as well as 292 objects from data…

Solar and Stellar Astrophysics · Physics 2015-06-11 R. Goldsbury , J. Heyl , H. B. Richer , P. Bergeron , A. Dotter , J. S. Kalirai , J. MacDonald , R. M. Rich , P. B. Stetson , P. -E. Tremblay , K. A. Woodley

In order to study the process of cooling in dark-matter (DM) halos and assess how well simple models can represent it, we run a set of radiative SPH hydrodynamical simulations of isolated halos, with gas sitting initially in hydrostatic…

Astrophysics · Physics 2009-11-13 M. Viola , P. Monaco , S. Borgani , G. Murante , L. Tornatore

The liquid metal-liquid silicate partitioning of molybdenum and tungsten during core formation must be well-constrained in order to understand the evolution of Earth and other planetary bodies, in particular because the Hf-W isotopic system…

Earth and Planetary Astrophysics · Physics 2022-10-26 E. S. Jennings , S. A. Jacobson , D. C. Rubie , Y. Nakajima , A. K. Vogel , L. A. Rose-Weston , D. J. Frost

We exploit the recent discovery of pulsations in mixed-atmosphere (He/H), extremely low-mass white dwarf precursors (ELM proto-WDs) to test the proposition that rotational mixing is a fundamental process in the formation and evolution of…

Solar and Stellar Astrophysics · Physics 2016-11-23 A. G. Istrate , G. Fontaine , A. Gianninas , L. Grassitelli , P. Marchant , T. M. Tauris , N. Langer

We present a prescription for parametrizing the chemical profile in the core of white dwarfs in the light of the recent discovery that pulsation modes may sometimes be deeply confined in some cool pulsating white dwarfs. Such modes may be…

Solar and Stellar Astrophysics · Physics 2017-01-18 N. Giammichele , S. Charpinet , G. Fontaine , P. Brassard

White dwarf (WD) binary mergers are possible progenitors to a number of unusual stars and transient phenomena, including type Ia supernovae. To date, simulations of mergers have not included magnetic fields, even though they are believed to…

Solar and Stellar Astrophysics · Physics 2015-06-11 Chenchong Zhu , Rudiger Pakmor , Marten H. van Kerkwijk , Philip Chang

The possible existence of warm ($T_{\rm eff}\sim19\,000$ K) pulsating DA white dwarf (WD) stars, hotter than ZZ Ceti stars, was predicted in theoretical studies more than 30 yr ago. However, to date, no pulsating warm DA WD has been…

Understanding the explosion mechanism of type Ia supernova is among the most challenging issues in astrophysics. Accretion of matter on a carbon-oxygen white dwarf from a companion star is one of the most important keys in this regard. Our…

Solar and Stellar Astrophysics · Physics 2023-05-10 Harish Kumar , Abhinav Gupta , Siddharth Savyasachi Malu , Shashikant Gupta

A convective dynamo operating during the crystallization of white dwarfs is one of the promising channels to produce their observed strong magnetic fields. Although the magnitude of the fields generated by crystallization dynamos is…

Solar and Stellar Astrophysics · Physics 2024-01-25 Daniel Blatman , Sivan Ginzburg

Compact binary white dwarfs (WDs) undergoing orbital decay due to gravitational radiation can experience significant tidal heating prior to merger. In these WDs, the dominant tidal effect involves the excitation of outgoing gravity waves in…

Solar and Stellar Astrophysics · Physics 2015-06-05 Jim Fuller , Dong Lai

Asteroid material is detected in white dwarfs (WDs) as atmospheric pollution by metals, in the form of gas/dust discs, or in photometric transits. Within the current paradigm, minor bodies need to be scattered, most likely by planets, into…

Earth and Planetary Astrophysics · Physics 2020-08-12 R. F. Maldonado , E. Villaver , A. J. Mustill , M. Chávez , E. Bertone

We report the most rapid rate of period change measured to date for a pulsating DA (hydrogen atmosphere) white dwarf (WD), observed in the 292.9 s mode of WD 0111+0018. The observed period change, faster than 10^{-12} s/s, exceeds by more…

Solar and Stellar Astrophysics · Physics 2015-06-15 J. J. Hermes , M. H. Montgomery , Fergal Mullally , D. E. Winget , A. Bischoff-Kim