Article

Blazhko RR Lyrae light curves as modulated signals

Monthly Notices of the Royal Astronomical Society (Impact Factor: 5.52). 06/2011; 417. DOI: 10.1111/j.1365-2966.2011.19313.x
Source: arXiv

ABSTRACT We present an analytical formalism for the description of Blazhko RR Lyrae
light curves in which employ a treatment for the amplitude and frequency
modulations in a manner similar to the theory of electronic signal
transmitting. We assume monoperiodic RR Lyrae light curves as carrier waves and
modulate their amplitude (AM), frequency (FM), phase (PM), and as a general
case we discuss simultaneous AM and FM. The main advantages of this handling
are the following: (i) The mathematical formalism naturally explains numerous
light curve characteristics found in Blazhko RR Lyrae stars such as mean
brightness variations, complicated envelope curves, non-sinusoidal frequency
variations. (ii) Our description also explains properties of the Fourier
spectra such as apparent higher-order multiplets, amplitude distribution of the
side peaks, the appearance of the modulation frequency itself and its
harmonics. In addition, comparing to the traditional method, our light curve
solutions reduce the number of necessary parameters. This formalism can be
applied to any type of modulated light curves, not just for Blazhko RR Lyrae
stars.

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