Related papers: Magnetic white dwarfs with debris disks

Double degenerate white dwarf (WD) mergers can exhibit extreme magnetic fields exceeding $10^{8}$ G and rapid rotation, but their spectral-energy distributions and high-energy emission mechanisms remain poorly characterised. ZTF J1901+1458…

I argue that the rotation of white dwarfs is not a remnant of the angular momentum of their main sequence progenitors but a result of the mass loss process on the AGB. Weak magnetic fields, if present in stellar interiors, are likely to…

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…

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…

We investigate whether the recently suggested rotation and crystallization driven dynamo can explain the apparent increase of magnetism in old metal polluted white dwarfs. We find that the effective temperature distribution of polluted…

White dwarfs (WDs) represent the final evolutionary stage of most stars, typically originating from progenitor stars with masses below approximately 8 $M_{\odot}$ to 10 $M_{\odot}$. Formation through single-star evolution generally requires…

We report the discovery of a rare close binary system, SMSS J160639.78-100010.7, comprised of a magnetic white dwarf with a field of about 30 MG and a brown dwarf. We measured an orbital period of 92 min which is consistent with the…

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…

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…

Close white dwarf binaries make up a wide variety of objects such as double white dwarf binaries, which are possible SN Ia progenitors, cataclysmic variables, super soft sources, or AM CVn stars. The evolution and formation of close white…

A population of anomalous ultra-massive white dwarfs discovered with Gaia, often referred to as the Q branch, show high (multi-Gyr) cooling delays produced by exotic physical mechanisms. They are believed to be the products of stellar…

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…

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…

Virtually all binaries consisting of a white dwarf with a non-degenerate companion can be classified as either close post-interaction systems (with orbital periods of a few days or less), or wide systems (with periods longer than decades),…

The rapidly evolving dust and gas extinction observed towards WD 1145+017 has opened a real-time window onto the mechanisms for destruction-accretion of planetary bodies onto white dwarf stars, and has served to underline the importance of…

Some short-period, detached binary systems have recently been reported to experience very rapid orbital decay, much faster than is expected from the angular-momentum loss caused by gravitational radiation alone. As these systems contain…

A significant fraction of isolated white dwarfs host magnetic fields in excess of a MegaGauss. Observations suggest that these fields originate in interacting binary systems where the companion is destroyed thus leaving a singular,…

We present 594 radial velocity measurements for 71 white dwarfs obtained during our search for binary white dwarfs and not reported elsewhere. We identify three excellent candidate binaries, which require further observations to confirm our…

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…

This review summarises recent observational results regarding the evolution of angular momentum and disks in brown dwarfs. The observations clearly show that brown dwarfs beyond ages of 10 Myr are exclusively fast rotators and do not spin…