Related papers: Intermediate-Mass Stars Become Magnetic White Dwar…
Magnetic fields generated by a dynamo mechanism due to differential rotation during stellar mergers are often proposed as an explanation for the presence of strong fields in certain classes of magnetic stars, including high field magnetic…
Binary systems of two carbon-oxygen white dwarfs are one of the most promising candidates for the progenitor systems of Type Ia supernovae. Violent mergers, where the primary white dwarf ignites when the secondary white dwarf smashes onto…
Polluted white dwarfs are generally accreting terrestrial-like material that may originate from a debris belt like the asteroid belt in the solar system. The fraction of white dwarfs that are polluted drops off significantly for white…
Type Ia supernovae, sparked off by exploding white dwarfs of mass close to Chandrasekhar limit, play the key role to understand the expansion rate of universe. However, recent observations of several peculiar type Ia supernovae argue for…
We find that $\sim 15-20$ per cent of A-type stars or red giants are bound with a massive companion ($M_{\rm secondary} > 1M_{\odot}$) in an intermediate wide orbit ($0.5<P<5000\mbox{ yr}$). These massive binaries are expected to form…
The prediction of the spins of the compact remnants is a fundamental goal of the theory of stellar evolution. Here, we confront the predictions for white dwarf spins from evolutionary models including rotation with observational…
Under the right conditions brown dwarfs that gain enough mass late in their lives to cross the hydrogen burning limit will not turn into low-mass stars, but rather remain essentially brown dwarf-like. While these objects, called either…
When the effective temperature of a cooling white dwarf $T_{\rm eff}$ drops below the ionization limit, it develops a surface convection zone that may generate a magnetic field $B$ through one of several dynamo mechanisms. We revisit this…
The white dwarf (WD) + helium (He) star binary channel plays an important role in the single degenerate scenario for the progenitors of type Ia supernovae (SNe Ia). Previous studies on the WD + main sequence star evolution have shown that…
White dwarfs typically have masses in a narrow range centered at about 0.6 solar masses (Msun). Only a few ultra-massive white dwarfs (M>1.2 Msun) are known. Those in binary systems are of particular interest because a small amount of…
White dwarfs are the remnants of stars not massive enough to become supernovae. This review explores the concept of strange dwarfs, a unique class of white dwarfs which contain cores of strange quark matter. Strange dwarfs have different…
We have expanded the sample of observed white dwarfs in the rich open cluster NGC 2099 (M37) with the Keck Low-Resolution Imaging Spectrometer. Of 20 white dwarf candidates, the spectroscopy shows 19 to be true white dwarfs with 14 of these…
Supernova Ia are bright explosive events that can be used to estimate cosmological distances, allowing us to study the expansion of the Universe. They are understood to result from a thermonuclear detonation in a white dwarf that formed…
We investigated the prospects for systematic searches of white dwarfs at low Galactic latitudes, using the VLT Survey Telescope (VST) H$\alpha$ Photometric Survey of the Galactic plane and Bulge (VPHAS+). We targeted 17 white dwarf…
Orbital decay mechanisms argue that double white dwarf mergers are inevitable, but extremely rare. Whilst some mergers result in explosions, the survivors re-ignite helium and burn brightly for tens of thousands or millions of years.…
The discovery of the existence of an upper bound on the mass of a white dwarf star is considered as one of the finest of twentieth century astrophysics. On approaching this limiting mass of $1.4M_\odot$, known as the Chandrasekhar…
There is a striking and unexplained dearth of brown dwarf companions in close orbits (< 3AU) around stars more massive than the Sun, in stark contrast to the frequency of stellar and planetary companions. Although rare and relatively…
In this work, we study the properties of magnetized white dwarfs taking into account possible instabilities due to electron capture and pycnonuclear fusion reactions in the cores of such objects. The structure of white dwarfs is obtained by…
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…
Most studies suggest the pollution of white dwarf (WD) atmospheres arises from accretion of minor planets, but the exact properties of polluting material, and in particular the evidence for water in some cases are not yet understood. Here…