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Related papers: Structure and evolution of ultra-massive white dwa…

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Taking advantage of the Gaia Data Release 2, recent studies have revisited the evolution of carbon-polluted white dwarfs (DQs) across a large range of effective temperatures. These analyses have clearly confirmed the existence of two…

Solar and Stellar Astrophysics · Physics 2019-11-06 S. Blouin , P. Dufour

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 investigate the structure and stability against radial oscillations, pycnonuclear reactions, and inverse $\beta$-decay of hot white dwarfs. We regard that the fluid matter is made up for nucleons and electrons confined in a Wigner-Seitz…

Solar and Stellar Astrophysics · Physics 2021-11-17 Sílvia P. Nunes , José D. V. Arbañil , Manuel Malheiro

We discuss the effects of rotation on the evolution of accreting carbon-oxygen white dwarfs, with the emphasis on possible consequences in Type Ia supernova (SN Ia) progenitors. Starting with a slowly rotating white dwarf, we simulate the…

Astrophysics · Physics 2009-11-10 S. -C. Yoon , N. Langer

White dwarf stars are the most common end point of stellar evolution. Of special interest are the ultramassive white dwarfs, as they are related to type Ia Supernovae explosions, merger events, and Fast Radio Bursts. Ultramassive white…

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…

Gaia Data Release 2 revealed a population of ultramassive white dwarfs on the Q branch that are moving anomalously fast for a local disc population with their young photometric ages. As the velocity dispersion of stars in the local disc…

Solar and Stellar Astrophysics · Physics 2023-04-07 Leesa Fleury , Ilaria Caiazzo , Jeremy Heyl

With the Keck I Low-Resolution Imaging Spectrometer we have observed nine white dwarf candidates in the very rich open cluster NGC 2099 (M37). The spectroscopy shows seven to be DA white dwarfs, one to be a DB white dwarf, and one to be a…

Solar and Stellar Astrophysics · Physics 2016-03-23 Jeffrey D. Cummings , Jason S. Kalirai , P. -E. Tremblay , Enrico Ramirez-Ruiz , P. Bergeron

White Dwarf luminosities are powerful age indicators, whose calibration should be based on reliable models. We discuss the uncertainty of some chemical and physical parameters and their influence on the age estimated by means of white dwarf…

Astrophysics · Physics 2009-11-07 P. G. Prada Moroni , O. Straniero

NGC 6397 is one of the most interesting, well observed and theoretically studied globular clusters. The existing wealth of observations allows us to study the reliability of the theoretical white dwarf cooling sequences of low metallicity…

Astrophysics of Galaxies · Physics 2015-09-23 S. Torres , E. García-Berro , L. G. Althaus , M. E. Camisassa

Seismological observations with the Whole Earth Telescope (WET) allow the determination of the subsurface compositional structure of white dwarf stars. The hot DO PG 1159 has a helium surface layer with a mass of 0.001 Msun, while the…

Astrophysics · Physics 2009-10-08 Benjamin T. Dehner , Steven D. Kawaler

We examine the emergent fluxes from helium-core white dwarfs following their evolution from the end of pre-white dwarf stages down to advanced cooling stages. For this purpose, we include a detailed treatment of the physics of the…

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

The properties of uniformly rotating white dwarfs (RWDs) are analyzed within the framework of Newton's gravity and general relativity. In both cases Hartle's formalism is applied to construct the internal and external solutions to the field…

Solar and Stellar Astrophysics · Physics 2015-03-16 Kuantay Boshkayev , Jorge A. Rueda , Remo Ruffini , Ivan Siutsou

With the precision now afforded by modern space-based photometric observations from the retired K2 and current TESS missions, the effects of general relativity (GR) may be detectable in the light curves of pulsating white dwarfs (WDs).…

Solar and Stellar Astrophysics · Physics 2023-07-24 S Reece Boston , Charles R Evans , J Christopher Clemens

As they evolve, white dwarfs undergo major changes in surface composition, a phenomenon known as spectral evolution. In particular, some stars enter the cooling sequence with helium atmospheres (type DO) but eventually develop hydrogen…

Solar and Stellar Astrophysics · Physics 2020-10-07 A. Bédard , P. Bergeron , P. Brassard , G. Fontaine

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 study the strongly magnetized white dwarf configurations in a self-consistent manner as a progenitor of the over-luminous type-Ia supernovae. We compute static equilibria of white dwarf stars containing a strong magnetic field and…

Solar and Stellar Astrophysics · Physics 2017-10-25 Prasanta Bera , Dipankar Bhattacharya

Observations of heavy metal pollution in white dwarf stars indicate that metal-rich planetesimals are frequently scattered into star-grazing orbits, tidally disrupted, and accreted onto the white dwarf surface, offering direct insight into…

Solar and Stellar Astrophysics · Physics 2018-02-21 E. Dennihy , J. C. Clemens , B. H. Dunlap , S. M. Fanale , J. T. Fuchs , J. J. Hermes

In this paper, we compare the currently available evolutionary tracks for Galactic massive stars. Our main goal is to highlight the uncertainties on the predicted evolutionary paths. We compute stellar evolution models with the codes MESA…

Solar and Stellar Astrophysics · Physics 2015-06-17 F. Martins , A. Palacios

White dwarfs are dense, cooling stellar embers consisting mostly of carbon and oxygen, or oxygen and neon (with a few percent carbon) at higher initial stellar masses. These stellar cores are enveloped by a shell of helium which in turn is…