Frequency analysis of HD 180642 (V1449 Aql)

Our goal is to analyse the detailed behaviour present in the light curve and interpret it in terms of excited-mode frequencies. After describing the noise properties in detail, we use various time series analyses and fitting techniques to model the CoRoT light curve, for various physical assumptions.

We apply statistical goodness-of-fit criteria that allow us to select the most appropriate physical model fit to the data. We conclude that the light-curve model based on nonlinear resonant frequency and phase locking provides the best representation of the data. Interpretation of the residuals is dependent on the chosen physical model used to prewhiten the data.