The relationship between infrared, optical, and ultraviolet extinction. An improved spectroscopic analysis of DA white dwarfs from the Sloan Digital Sky Survey Data Release 4. Stationary hydrogen lines in white dwarf magnetic fields and the spectrum of the magnetic degenerate GRW + 70 8247. Hydrogen spectrum in magnetic white dwarfs: H alpha, H beta and H gamma transitions. Hydrogen atoms in arbitrary magnetic fields.
Summary of the contents and survey properties. Using conditional entropy to identify periodicity. A Gaia Data Release 2 catalogue of white dwarfs and a comparison with SDSS. Orbital decay in a 20 minute orbital period detached binary with a hydrogen-poor low-mass white dwarf. General relativistic orbital decay in a seven-minute-orbital-period eclipsing binary system. Wind competing against settling: a coherent model of the GW Virginis instability domain. Pulsations of pre-white dwarfs with hydrogen-dominated atmospheres. Introduction of time-dependent convection. The instability strip of ZZ Ceti white dwarfs. The potential of white dwarf cosmochronology. Calibration of synthetic photometry using DA white dwarfs.
#White dwarf magazine july 2018 Pc#
The 100 pc white dwarf sample in the SDSS footprint. Gravitational settling of 22Ne in liquid white dwarf interiors: cooling and seismological effects. Cooling models for the most massive white dwarfs. The importance of Urca-process cooling in accreting ONe white dwarfs. Discovery of a hot ultramassive rapidly rotating DBA white dwarf. Constraints on the origin of the massive, hot, and rapidly rotating magnetic white dwarf RE J 0317–853 from an HST parallax measurement. Külebi, B., Jordan, S., Nelan, E., Bastian, U. The long-term evolution of double white dwarf mergers. Model properties at non-solar metallicity and the fate of super-AGB stars. The evolution of ultra-massive white dwarfs. The Swift Ultra-Violet/Optical Telescope. EUVE J0317–855: a rapidly rotating, high-field magnetic white dwarf. Quantum Mechanical Treatment and Applications in Astrophysics and Quantum Chaos (Springer, 1994).įerrario, L., de Martino, D. The Keck Low-Resolution Imaging Spectrometer. White dwarf rotation as a function of mass and a dichotomy of mode line widths: Kepler observations of 27 pulsating DA white dwarfs through K2 Campaign 8. CHIMERA: a wide-field, multi-colour, high-speed photometer at the prime focus of the Hale telescope. The Zwicky Transient Facility: system overview, performance, and first results. Evolutionary models for the remnant of the merger of two carbon-oxygen core white dwarfs. Double degenerate mergers as progenitors of high-field magnetic white dwarfs. Binary star origin of high field magnetic white dwarfs. The structure and fate of white dwarf merger remnants. Every interacting double white dwarf binary may merge. A systematic search of Zwicky Transient Facility data for ultracompact binary LISA-detectable gravitational-wave sources.
Ninety-eight double white dwarf binaries. ZTF J190132.9+145808.7 is likely to be cooling through the Urca processes (neutrino emission from electron capture on sodium) because of the high densities reached in its core.īrown, W. Such a small radius implies that the star’s mass is close to the maximum white dwarf mass, or Chandrasekhar mass. Here we report observations of a white dwarf, ZTF J190132.9+145808.7, that exhibits these properties, but to an extreme: a rotation period of 6.94 minutes, a magnetic field ranging between 600 megagauss and 900 megagauss over its surface, and a stellar radius of \(\) kilometres, only slightly larger than the radius of the Moon. In the latter case, the white dwarf remnant is expected to be highly magnetized 5, 6 because of the strong magnetic dynamo that should arise during the merger, and be rapidly spinning from the conservation of the orbital angular momentum 7. Depending on the component masses, the merger can lead to a supernova of type Ia or result in a massive white dwarf 4. If the orbital period of the binary is short enough, energy losses from gravitational-wave radiation can shrink the orbit until the two white dwarfs come into contact and merge 3. White dwarfs represent the last stage of evolution of stars with mass less than about eight times that of the Sun and, like other stars, are often found in binaries 1, 2.