We started a new project which aims to find compact hot subdwarf binaries at low Galactic latitudes. Targets are selected from several photometric surveys and a spectroscopic follow-up campaign to find radial velocity variations on timescales as short as tens of minutes has been started. Once radial variations are detected phase-resolved spectroscopy is obtained to measure the radial velocity curve and the mass function of the system. The observing strategy is described and the discovery of two short period hot subdwarf binaries is presented. UVEXJ032855.25+503529.8 contains a hot subdwarf B star (sdB) orbited by a cool M-dwarf in a P=0.11017 days orbit. The lightcurve shows a strong reflection effect but no eclipses are visible. HS 1741+2133 is a short period (P=0.20 days) sdB most likely with a white dwarf (WD) companion.
@article{arxiv.1308.2447,
title = {Finding compact hot subdwarf binaries in the Galactic disc},
author = {T. Kupfer and S. Geier and A. Faye McLeod and P. J. Groot and K. Verbeek and V. Schaffenroth and U. Heber and C. Heuser and E. Ziegerer and R. Østensen and P. Nemeth and V. S. Dhillon and T. Butterley and S. P. Littlefair and R. W. Wilson and J. H. Telting and A. Shporer and B. J. Fulton},
journal= {arXiv preprint arXiv:1308.2447},
year = {2013}
}
Comments
8 pages and 5 figures; to be published in the proceedings of the Sixth Meeting on Hot Subdwarf Stars and Related Objects