New photometry of ten eclipsing white dwarf/ red dwarf binary stars

Abstract

For nine of the stars light curves were obtained in (Formula presented), for the tenth observations also included the B filter. The periods of the stars are short, ranging from 0.12 to 0.19 d. The compact nature of the hotter star is evident from the steepness of the primary eclipse ingress/egress, while the de-reddened colours suggest that the secondary stars are M dwarfs. Accurate temperatures and luminosities of the red components are derived from published standardized photometry and parallaxes. The results of modelling the light curves using the well known Wilson–Devinney software are presented. Half the binaries are found to be semi-detached. The lack of overt signs of substantial mass transfer suggests that contact is marginal. The remaining five systems are best modelled as being in detached configurations. The white dwarf components are cool, effective temperatures with one exception being below 7000 K.