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N Jevtic (Richard Stockton College of New Jersey), J.A. Mattei (AAVSO), J.S. Schweitzer (University of Connecticut)
A nonlinear time series analysis was conducted of ~100 years of daily AAVSO intensity data for SS Cygni. Poincare section return times for the phase space portrait, obtained using the time delay method, indicate a possible periodicity of ~52 years in the time between successive outburst maxima. Recurrence plot analysis shows that the minima of the curve of the times between successive outbursts coincide with short intervals during which outbursts are considerably smaller and occur with greater frequency. Local correlation dimension calculations give a value greater by one for the system outside these minima and imply two different dynamic regimes. Thus, recurrence plot analysis, in the case of the SS Cygni data, is an efficient tool for identifying abrupt, short-term changes in the dynamics within this long time series. There is a risk that these more rapid, small outbursts could be overlooked if traditional averaging methods are used. The significance of the change in outburst size and frequency for the dynamics of the system is currently being evaluated.
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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.