21st European White Dwarf Workshop
Recent Submissions
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An Exploration of Spotted White Dwarfs from K2
(2018-07)The Kepler K2 mission has discovered a significant population of white dwarf stars that exhibit photometric variability due to surface inhomogeneities likely related to magnetism. These “spotted” white dwarfs present ... -
Evolutionary and Pulsational Properties of Ultra-massive White Dwarfs. The Role of Oxygen-Neon Phase Separation.
(2018-07)Ultra-massive hydrogen-rich white dwarf stars are expected to harbour oxygen/neon cores resulting from semidegenerate carbon burning when the progenitor star evolves through the super asymptotic giant branch (S-AGB) ... -
Blue Large-Amplitude Pulsators (BLAPs): Possible Origin, Evolutionary Status, and Nature of their Pulsations
(2018-07)The Blue Large-Amplitude Pulsators (BLAPs) constitute a new class of pulsating stars. They are hot stars with effective temperatures of Teff ~ 30000 K and surface gravities of log g ~ 4.9, that pulsate with periods ... -
Asteroseismological Study on PG 0112+104 with Pure and Screened Coulomb Potential
(2018-07)With 78.7 days of observations by Kepler space telescope, Hermes et al. (2017) made a detailed mode identification on a hot DBV star PG 0112+104. In total, 11 likely m = 0 components with 5 triplets and 3 quintuplets ... -
Evolution and Asteroseismology of Pulsating Low-Mass White Dwarfs
(2018-07)Many low-mass white dwarfs are being discovered in the field of our galaxy and some of them exhibit g-mode pulsations, comprising the extremely low-mass variable (ELMV) stars class. Although it is generally believed ... -
Constraining Low-Mass White Dwarf Binaries from Ellipsoidal Variations
(2018-07)Stars are stretched by tidal interactions in tight binaries, and changes to their projected areas introduce photometric variations twice per orbit. Hermes et al. (2014) utilized measurements of these ellipsoidal ... -
Limits on Mode Coherence Due to a Non-static Convection Zone
(2018-07)The standard theory of pulsations deals with the frequencies and growth rates of infinitesimal perturbations in a stellar model. Modes which are calculated to be linearly driven should increase their amplitudes ... -
High-precision Atomic Physics Laboratories in Space: White Dwarfs and Subdwarfs
(2018-07)Stellar atmospheres are prime laboratories to determine atomic properties of highly ionized species. Reliable opacities are crucial ingredients for the calculation of stellar atmospheres of white dwarfs and subdwarfs. ... -
An Update on Pulsations in Accreting White Dwarfs
(2018-07)Since the last white dwarf workshop, there is continuing evidence that long (hrs to days) periodicities are being found in white dwarfs that are undergoing accretion in close binary systems. Pulsation modes remain a ... -
Numerical simulations of the convective dilution process in helium-rich white dwarfs
(2018-07)DB and DBA white dwarfs are generally believed to be the result of a process by which a thin radiative hydrogen atmosphere floating in diffusive equilibrium on top of a helium envelope is eventually completely diluted ... -
Magnetic Torques Imply Fewer Double Detonations
(2018-07)Binary systems composed of one helium-rich nondegenerate star and one carbon-oxygen white dwarf (He+CO) have long been considered a promising progenitor candidate for a number of astrophysical transients like archetypical ... -
The gravitational redshift of Sirius B
(2018-07)Previous measurements of the gravitational redshift of Sirius B have resulted in a mass estimate which is significantly larger than the mass measured from the binary orbit. We have obtained new HST observations of ... -
White dwarf collisions and the meteoritic Ne-E anomaly
(2018-07)The analysis of noble gases in primitive meteorites has shown the existence of anomalous isotopic abundances when compared with the average Solar System values. In particular it has been found that some graphite grains ... -
A New Look at Magnetic White Dwarfs
(2018-07)We present a homogeneous photometric analysis of a large sample of magnetic DA white dwarfs as well as selected results from a spectrophotometric analysis of magnetic carbon-dominated atmosphere white dwarfs. We find ... -
A Precise Radial Velocity Search for Giant Planets orbiting polluted White Dwarfs
(2018-07)We present a feasibility study for extending the well-known radial velocity technique to search for planetary companions around white dwarfs. Typically, the spectra of white dwarfs contain only a few pressure-broadened ... -
Dusty Exoplanetary Debris Disks in the Single-Temperature Blackbody Plane
(2018-07)We present a bulk sample analysis of the metal polluted white dwarfs which also host infrared bright dusty debris disks, known to be direct signatures of an active exoplanetary accretion source. We explore the relative ... -
Evolutionary and pulsational properties of ultra-massive white dwarfs. The role of oxygen-neon phase separation.
(2018-07)Ultra-massive hydrogen-rich white dwarfs (WDs) are expected to harbor oxygen/neon cores resulting from semi-degenerate carbon burning when the progenitor star evolves through the super asymptotic giant branch (SAGB) ... -
Improved and Tested: A New Generation of Cool White Dwarf Atmosphere Models
(2018-07)The photosphere of cool, helium-rich white dwarfs is notoriously tricky to model due to its fluid-like density. Using modern ab initio calculations, we have developed a new generation of atmosphere models that include ... -
Luminosity and cooling suppression in magnetized white dwarfs
(2018-07)We investigate the luminosity and cooling of highly magnetized white dwarfs where cooling occurs by the diffusion of photons. We solve the magnetostatic equilibrium and photon diffusion equations to obtain the temperature ... -
Constraining the Milky Way potential with Double White Dwarfs
(2018-07)The upcoming LISA mission is the only experiment that will allow us to study the Milky Way’s structure using gravitational wave signals from Galactic double white dwarfs (DWDs). The total number of expected detections ...
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