SIMBAD references

Combining data from various sources we present a visual light curve of the symbiotic star Z Andromedae, covering continuously 98 years of this star's photometric history. Time series analysis reveals a clear, coherent periodicity of 759days in the light curve, with epoch of minimum light at JD 2442666. We identify this period as the binary period of the star. During outbursts, the star enters an oscillation mode with a quasi-period of 656days. These oscillations may include a stable, coherent component with a period of 667days. A third periodicity of ∼5500days is also present in the data. It is the beat period between the binary and the high state cycles of Z And. It is found in the light curve of the low state of the star. The light variability of Z And during two, and possibly also a third, major outbursts, out of the 5 observed in the last 98years, may be fitted to a model of damped driven oscillator.