Events in Physics
Pierre Maxted (Keele University)
Stripped red giant stars in eclipsing binary systems
Red giant stars can be stripped of their outer layers by stellar collisions or mass transfer in binary star systems such as low mass X-ray binaries. If the red giant is stripped on its first ascent of the RGB it will eventually become a very low mass white dwarf composed almost entirely of helium. Very low mass white dwarfs are well known in binary milli-second pulsars and many have recently been found in surveys such as the SDSS, but the precursor phase during which the remnant evolves to higher effective temperature at nearly constant
luminosity has been rarely observed. In this talk I will present new observations of 18 bright eclipsing binary stars discovered in WASP archive that contain stripped red giant stars. The first such binary we identified was also found to be a new type of pulsating star. This opens up the possibility of studying the interior strucuture of these helium white dwarf precursors in unprecendented detail.