An Alternative Mathematical Treatment of the Modulated RR Lyrae Stars

We present a different analytical description of the Blazhko RR Lyrae stars’s light curves in which we take into account both the amplitude and phase modulation directly. Its main advantages compared to the usual description are that it explains global light curve behaviours such as average brightness variation, non‐linear shape of the envelope curve, non‐sinusoidal frequency variation (see [1]). Its spectra show Fourier properties such as higher order side frequencies, uneven amplitudes of side peaks, larger amplitudes of higher order peaks than the lower order ones, appearing the modulation frequency itself and its harmonics. It also reduces the number of necessary parameters by a factor of 10.