Related papers: Observing and modelling magnetic fields in white d…
The evolution of the magnetic field is investigated for isolated as well as binary neutron stars. The overall nature of the field evolution is seen to be similar for an initial crustal field and an expelled flux. The major uncertainties of…
Observations of active M dwarfs show a broad variety of large-scale magnetic fields encompassing dipole-dominated and multipolar geometries. We detail the analogy between some anelastic dynamo simulations and spectropolarimetric…
Possible nature of strongly magnetized white dwarfs (SMWDs) is studied. It is shown that for relatively low values of the equatorial surface magnetic field $B\,\sim\,10^9\,-\,10^{11}$ G they can be good candidates for soft gamma-ray…
Recent studies reveal that more than a dozen of white dwarfs displaying near-perfect blackbody spectra in the optical range have been lurking in the Sloan Digital Sky Survey catalog. We point out that, in a way analogous to the Cosmic…
We consider the effects of rotation and temperature on the structure of white dwarfs in order to compare them with the estimated data from observations.
With the first observations of debris disks as well as proposed planets around white dwarfs, the question of how rocky planets around such stellar remnants can be characterized and probed for signs of life becomes tangible. White dwarfs are…
With the Cosmic Origins Spectrograph onboard the Hubble Space Telescope, we have detected molecular hydrogen in the atmospheres of three white dwarfs with effective temperatures below 14,000 K, G29-38, GD 133 and GD 31. This discovery…
An arbitrary initial magnetic field in an A star evolves into a stable equilibrium. Simulations are presented of the formation of non-axisymmetric equilibria consisting of twisted flux tubes meandering under the surface of the star, and…
The magnetic fields of white dwarfs distort their shape generating an anisotropic moment of inertia. A magnetized white dwarf which rotates obliquely relative to the symmetry axis has a mass quadrupole moment which varies in time, so it…
The aim of the Degenerate Objects around Degenerate Objects (DODO) survey is to search for very low mass brown dwarfs and extrasolar planets in wide orbits around white dwarfs via direct imaging. The direct detection of such companions…
We compare measured element abundances in hot DA white dwarfs from UV observations to predictions from our self-consistent non-LTE model atmosphere diffusion calculations.
The values of electrical conductivity of plasma of stars with a magnetic field or moving in the magnetic field of the other component in a binary system could be of significant interest, since they are useful for the study of thermal…
Situation with highly magnetized neutron stars in binary systems is not yet certain. On the one hand, all best studied magnetars seem to be isolated objects. On the other, there are many claims based on model-dependent analysis of spin…
Recent determinations of the white dwarf luminosity function (WDLF) from very large surveys have extended our knowledge of the WDLF to very high luminosities. It has been shown that the shape of the luminosity function of white dwarfs…
We report first results of our systematic investigation of the magnetic field structure of rotating single magnetic white dwarfs and of white dwarfs in magnetic cataclysmic variables. The global magnetic field distributions on the isolated…
The properties of the extremely strong magnetic fields of neutron stars affect in a unique way their evolution and the associated phenomenology. Due to the lack of constraints from direct observations, our understanding of the magnetic…
Magnetic fields are regarded as a crucial element for our understanding of stellar physics. They can be studied with a variety of methods which provide complementary - and sometimes contradictory - information about the structure, strength…
In the past few years, astronomers have uncovered several very low-temperature, metal-poor stars with halo or thick disk kinematics and peculiar spectral and photometric properties, so-called ultracool subdwarfs. These include the first…
A detailed analysis of halo white dwarf candidates is presented, which is based on model atmosphere fits to observed energy distributions built from photoelectric or photographic magnitudes. Most of the candidates identified in reduced…
White dwarf stars are the most common endpoint of stellar evolution. Therefore, these old, numerous and compact objects provide valuable information on the late stages of stellar evolution, the physics of dense plasma and the structure and…