Orbits of Post-AGB Stars with Dusty Discs

Abstract

Abstract. Optical photometry and radial velocities have been obtained for stars whose nearand mid-infrared colours suggest that they have dusty circumstellar discs; many are RV Tauri variables. A subset of six stars have earlier spectral types and smaller light amplitudes than classical RV Tauri stars. All are spectroscopic binaries, with surprisingly short periods.