1 citations · 3 across the 6 of their papers we have counts for
6 papers
Metal Abundances of Subdwarf B Stars from SPY - a Pattern Emerges
S. Geier, U. Heber, R. Napiwotzki
The formation of sdBs is still puzzling, as is the chemical composition of their atmospheres. While helium and other light elements are depleted relative to solar values, heavy ele…
Binary sdB Stars with Massive Compact Companions
S. Geier, C. Karl, H. Edelmann +2
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…
Radial Velocity Variable sdO/Bs from SPY - Preliminary Orbits of Three New Short Period Binaries
S. Geier, U. Heber, R. Napiwotzki
We present new results from follow-up time-resolved spectroscopy of radial velocity variable hot subdwarfs from the SPY project. Medium resolution spectra were taken at the ESO NTT…
Tidal synchronization of the subdwarf B binary PG 0101+039
S. Geier, S. Nesslinger, U. Heber +3
Tidally locked rotation is a frequently applied assumption that helps to measure masses of invisible compact companions in close binaries. The calculations of synchronization times…
Spectroscopic Analysis of subluminous B Stars in Binaries with compact Companions
S. Geier, C. Karl, H. Edelmann +2
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…
The subdwarf B + white dwarf binary KPD 1930+2752 - a Supernova Type Ia progenitor candidate
S. Geier, S. Nesslinger, U. Heber +3
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 candidates known today. The object is a d…