"What mimics the reflection effect in symbiotic binaries?"@en . . "2001"^^ . "2001"^^ . . . "We discuss the origin of a periodic wave-like variation as a function of the orbital phase observed in the light curves (LC) of symbiotic stars. It is shown that this type of variability cannot be ascribed to a reflection effect. For example, the observed amplitudes of the LCs are far larger than those calculated within a model of the reflection effect. Here, the nature of the orbitally related changes in the optical continuum is outlined within an ionization model of symbiotic binaries."@en . . . . "ESO" . . . "aa9660" . . . . "\u00A9 ESO, 2001" .