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The Subdwarf B + White Dwarf Binary KPD 1930+2752, a Supernova Type Ia Progenitor Candidate
(Astronomical Society of the Pacific, 2007)
The nature of the progenitors of type Ia supernovae is still under controversial debate. KPD 1930+2752 is one of the best SN Ia progenitor can- didates known today. The object is a double degenerate system consisting of a ...
The Fraction of DA White Dwarfs with Kilo-Gauss Magnetic Fields
(Astronomical Society of the Pacific, 2007)
Current estimates for white dwarfs with fields in excess of 1MG are about 10%; according to our first high-precision circular-polarimetric study of 12 bright white dwarfs with the VLT (Aznar Cuadrado et al. 2004) this ...
The Origins of the Ultramassive White Dwarf GD50
(Astronomical Society of the Pacific, 2007)
On the basis of astrometric and spectroscopic data we argue that the ultramassive white dwarf GD 50 is associated with the star formation event that created the Pleiades and is potentially a former cluster member. Its ...
Follow-up Observations of SPY White Dwarf + M-Dwarf Binaries
(Astronomical Society of the Pacific, 2007)
We present the results of follow-up observations of white-dwarf + M-dwarf binaries identified using spectra obtained as part of the SPY survey. Spectra of the Hα region were obtained with the SPIRAL spectrograph on the AAT ...
Spectroscopic Analysis of Subluminous B Stars in Binaries with Compact Companions
(Astronomical Society of the Pacific, 2007)
The masses of compact objects like white dwarfs, neutron stars and black holes are fundamental to astrophysics, but very difficult to measure. We present the results of an analysis of subluminous B (sdB) stars in close ...