We report the discovery of two new hot, hydrogen-rich subdwarfs (sdB) in
close binary systems. The hot subdwarfs, GALEX J0321+4727 and GALEX J2349+3844,
were selected from a joint optical-ultraviolet catalogue of hot sub-luminous
stars based on GSC2.3.2 and the Galaxy Evolution Explorer all-sky survey. Using
high-dispersion spectra of the Halpha core obtained using the 2m telescope at
Ondrejov Observatory we measured the radial velocities of the sdB primaries and
determined orbital periods of 0.26584+/-0.00004 days and 0.46249+/-0.00007 days
for GALEX J0321+4727 and GALEX J2349+3844, respectively. The time series
obtained from the Northern Sky Variability Survey with an effective wavelength
near the R band show that GALEX J0321+4727 is a variable star (Delta m=0.12
mag) while no significant variations are observed in GALEX J2349+3844. The
period of variations in GALEX J0321+4727 coincides with the orbital period and
the variability is probably caused by a reflection effect on a late-type
secondary star. Lack of photometric variations in GALEX J2349+3844 probably
indicates that the companion is a white dwarf star. Using all available
photometry and spectroscopy, we measured the atmospheric properties of the two
sdB stars and placed limits on the mass and luminosity of the companion stars.Comment: Accepted for publication in MNRA
