2008CoAst.153....8C

An approach sometimes used to determine the dominant period of a doublemode pulsating star with strong beats in its light curve is to find (O-C) for an observing season by averaging the individual values obtained from observed times of maximum light. The long-term graph of (O-C) versus time can then be used to determine the period and its rate of change.
Method. of determining the secondary period usually involve Fourier analysis of relatively complete sets of photometric data. We show that the beat-curve method, e.g., Elst (1973), Coates et al. (1979, 1982) is an alternative approach also worth considering. The offset of the beat curve usually yields a more precise value of (O-C) for a season than a simple average does, the phase of the beat curve leads to an estimate of the secondary period without the need for intensive photometry, and the amplitude of the beat curve provides information about the relative amplitudes of the modes of oscillation of the star.