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Kilo-Gauss Magnetic Fields in Three DA White Dwarfs
(Astronomical Society of the Pacific, 2005)
We have detected longitudinal magnetic fields between 2 and 4 kG in three normal DA white dwarfs (WD0446¡790, WD1105¡048, WD2359¡434) out of a sample of 12 by using optical spectropolarimetry done with the VLT Antu 8 m ...
Identification of a DO White Dwarf and a PG1159 Star in the ESO SN Ia Progenitor Survey (SPY)
(Astronomical Society of the Pacific, 2005)
We present high-resolution VLT spectra of a new DO white dwarf and a new PG1159 star, which we identified in the ESO SPY survey. The PG1159 star is a low-gravity, extremely hot (Te® = 160 000 K, log g = 6) star, having a ...
Rotation Velocities of DA White Dwarfs with Convective Atmospheres
(Astronomical Society of the Pacific, 2005)
The sharp H® NLTE line cores of hydrogen rich (DA) white dwarfs allow their projected rotational velocities to be determined. High resolution optical spectra of 22 stars obtained with the Keck I telescope are matched by ...
The Mass of the sdB Primary of the Binary HS 2333+3927
(Astronomical Society of the Pacific, 2005)
Short period sdB binaries with cool companions are crucial to understand pre-CV evolution, because they will evolve into cataclysmic variables, when the sdB will have left the extended horizontal branch. Recently we ...
Subdwarf B Stars from the ESO Supernova Ia Progenitor Survey -- Observation versus Theory
(Astronomical Society of the Pacific, 2005)
We present the analysis of a high-quality sample of optical spectra for 76 sdB stars from the ESO Supernova Ia Progenitor Survey. Effective temperature, surface gravity, and photospheric helium abundance were derived from ...