Abstract

Contributed Talk - Splinter CloseBinaries   (MW-0250)

New Hot Subdwarf Binaries from a SOAR Spectroscopic Survey

Fabian Mattig (1), Brad Barlow (2), Matti Dorsch (1), Stephan Geier (1), Harry Dawson (1)
(1) Universität Potsdam, (2) University of North Carolina

Short-period binary systems involving hot subdwarf stars (sdO/Bs) are products of binary evolution. As such, they are key sources of information both about the processes that formed them, like Common Envelope phases and Roche lobe overflow, and about supernovae of type Ia, to which certain hot subdwarfs in close orbits with white dwarf stars (WDs) can be progenitors. In order to form a broad observational foundation for close binaries hiding in the currently known catalogues of hot subdwarf stars, we observed 843 low-resolution SOAR spectra of candidate radial velocity variable targets. Combined with all available photometric and archival spectroscopic data for the potential close binaries we investigated, we determined accurate orbital solutions for 12 previously unknown systems. In this talk I will present the results of this large survey including the radial velocity statistics across the hot subdwarf catalogue and highlight especially interesting systems, such as a new eclipsing sdB+WD binary.