Observational data of the light curve of the variable star R Scuti are subjected to a powerful recently developed nonlinear dynamics approach. This is the first time it is shown that the irregular pulsations of a star are described by a chaotic dynamics with an embedding dimension of 4. The results are relatively robust with respect to the presmoothing of the observational data, as well as to the parameters of the method (such as the delay and sampling rate). This low dimension suggests that the complex pulsational behavior is a result of the nonlinear interactions between just two vibrational modes.

• Received 18 July 1994

DOI:https://doi.org/10.1103/PhysRevLett.74.842