SIMBAD references

O-type hot subdwarf (sdO) stars are evolved objects linking the asymptotic giant branch and extended horizontal branch phases with the dying low-mass white dwarfs. However, their exact evolutionary state and inner structure has not yet been constrained. Our aim was to discover possible sdO pulsators, so that asteroseismologic techniques could be used to unveil their inner structure and evolutionary state. We performed fast CCD photometry in search of pulsators within a sample of 56 sdOs in the Northern and Southern hemispheres during the period 2003-2006. We obtained two very promising sdO pulsator candidates that remain to be confirmed due to the low amplitude of their oscillations.