Advanced stages of stellar evolution involving white dwarf stars and hot subdwarf stars.
Binary origins of hot subdwarf stars: orbital studies, studies of the binary companions, evolutionary pathways, and population synthesis.
Distances to planetary nebulae from photometric observations of their companion stars.
A dynamical mass for TU Ursae Majoris, an RR Lyrae star in a 23-year binary.
Accurate masses and radii of low-mass dwarf stars.
Observations and models of accretion disks in cataclysmic variable systems.