A study of the outburst development in the classical symbiotic star Z and within the colliding-winds model

Two-dimensional gas-dynamical modeling of the mass-flow structures in binary systems is used to study the outburst development in the classical symbiotic star Z And. The stage-by-stage rise of the light during the outburst can be explained using a model with colliding winds. We suggest a scenario for the development of the outburst and study the influence of possible changes in the flow structure on the brightness of the system. The model variations of the luminosity due to the formation of a system of shocks are in good agreement with the observed brightness variations.