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Related papers: Magnetic white dwarfs with debris discs

200 papers

Recent surveys of close white dwarf binaries as well as single white dwarfs have provided evidence for the late appearance of magnetic fields in white dwarfs, and a possible generation mechanism a crystallization and rotation-driven dynamo…

We investigate the evolution of isolated, zero and finite temperature, massive, uniformly rotating and highly magnetized white dwarf stars under angular momentum loss driven by magnetic dipole braking. We consider the structure and thermal…

Solar and Stellar Astrophysics · Physics 2019-05-29 Laura Becerra , Kuantay Boshkayev , Jorge. A. Rueda , Remo Ruffini

Observational estimates of the lifetimes and inferred accretion rates from debris discs around polluted white dwarfs are often inconsistent with the predictions of models of shielded Poynting-Robertson drag on the dust particles in the…

Solar and Stellar Astrophysics · Physics 2021-01-05 Miriam A Hogg , Ry Cutter , Graham Wynn

The absence of magnetic white dwarfs with a non-degenerate low-mass stellar companion in a wide binary is still very intriguing and at odds with the hypothesis that magnetic white dwarfs are the progenies of the magnetically peculiar Ap/Bp…

Solar and Stellar Astrophysics · Physics 2018-10-16 Lilia Ferrario

Magnetic fields can play an important role in stellar evolution. Among white dwarfs, the most common stellar remnant, the fraction of magnetic systems is more than 20 per cent. The origin of magnetic fields in white dwarfs, which show…

Solar and Stellar Astrophysics · Physics 2022-04-27 Ingrid Pelisoli , M. Dorsch , U. Heber , B. Gänsicke , S. Geier , T. Kupfer , P. Németh , S. Scaringi , V. Schaffenroth

Rotation has a number of important effects on the evolution of stars. It decreases the surface gravity, causes enhanced mass loss and leads to surface abundance anomalies of various chemical isotopes. We have adapted the Cambridge stellar…

Solar and Stellar Astrophysics · Physics 2012-05-31 Adrian T. Potter

The evolution of the remnant of the merger of two white dwarfs is still an open problem. Furthermore, few studies have addressed the case in which the remnant is a magnetic white dwarf with a mass larger than the Chandrasekhar limiting…

Solar and Stellar Astrophysics · Physics 2018-05-02 L. Becerra , J. A. Rueda , P. Loren-Aguilar , E. Garcia-Berro

Accretion-driven spin-up of a magnetized white dwarf in a close binary system is discussed. We address a situation in which the magnetic field of the white dwarf is screening during the accretion phase and re-generating due to the field…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Nazar Ikhsanov , Nina Beskrovnaya

Many stars evolve into magnetic white dwarfs, and observations may help to understand when the magnetic field appears at the stellar surface, if and how it evolves during the cooling phase, and what are the mechanisms that generate it.…

Solar and Stellar Astrophysics · Physics 2021-10-04 S. Bagnulo , J. D. Landstreet

Many magnetic white dwarfs exhibit a polarised spectrum that periodically varies as the star rotates because the magnetic field is not symmetric about the rotation axis. In this work, we report the discovery that while weakly magnetic white…

Solar and Stellar Astrophysics · Physics 2024-11-18 S. Bagnulo , J. D. Landstreet

The surface magnetic field strength of white dwarfs is observed to vary from very little to around 10^9 G. Here we examine the proposal that the strongest fields are generated by dynamo action during the common envelope phase of strongly…

Solar and Stellar Astrophysics · Physics 2009-12-12 Adrian T. Potter , Christopher A. Tout

Stellar mergers are one important path to highly magnetised stars. Mergers of two low-mass white dwarfs may create up to every third hot subdwarf star. The merging process is usually assumed to dramatically amplify magnetic fields. However,…

We argue that the quiescent value of the viscosity parameter of the accretion disc in WZ Sge may be alpha_{cold}~0.01, in agreement with estimates of alpha_{cold} for other dwarf novae. Assuming the white dwarf in WZ Sge to be magnetic, we…

Astrophysics · Physics 2008-11-26 O. M. Matthews , R. Speith , G. A. Wynn , R. G. West

We describe the evolution of double degenerate binary systems, consisting of components obeying the zero temperature mass radius relationship for white dwarf stars, from the onset of mass transfer to one of several possible outcomes…

Astrophysics · Physics 2008-11-26 Vayujeet Gokhale , Xiao Meng Peng , Juhan Frank

We perform hydrodynamic simulations of mass transfer in binaries that contain a white dwarf and a neutron star (WD-NS binaries), and measure the specific angular momentum of material lost from the binary in disc winds. By incorporating our…

High Energy Astrophysical Phenomena · Physics 2017-02-09 Alexey Bobrick , Melvyn B. Davies , Ross P. Church

I review, from an observational perspective, the interactions of accretion discs with magnetic fields in cataclysmic variable stars. I start with systems where the accretion flows via a stream, and discuss the circumstances in which the…

Astrophysics · Physics 2009-11-13 Coel Hellier

In a series of recent papers, it has been proposed that high field magnetic white dwarfs are the result of close binary interaction and merging. Population synthesis calculations have shown that the origin of isolated highly magnetic white…

Solar and Stellar Astrophysics · Physics 2018-10-16 Gordon P. Briggs , Lilia Ferrario , Christopher A. Tout , Dayal T. Wickramasinghe

The main aim in the current survey is to suggest models of the development of structures, such as vortices and spirals, in accretion white dwarf's binaries. Numerical methods and simulations are applied on the bases of hydrodynamic…

Solar and Stellar Astrophysics · Physics 2015-05-27 Daniela Boneva

It has been recently suggested that white dwarfs generate magnetic fields in a process analogous to the Earth. The crystallization of the core creates a compositional inversion that drives convection, and combined with rotation, this can…

Solar and Stellar Astrophysics · Physics 2022-05-25 Sivan Ginzburg , Jim Fuller , Adela Kawka , Ilaria Caiazzo

Numerical simulations suggest that merging double white dwarfs (WDs) may produce a newborn neutron star surrounded by a fossil disk. We investigate the evolution of the fossil disk following the coalescence of double WDs. We demonstrate…

High Energy Astrophysical Phenomena · Physics 2015-10-27 Bai-Sheng Liu , Xiang-Dong Li