Is the Blazhko effect the beating of a near-resonant double-mode pulsation? [SSA]

http://arxiv.org/abs/1408.0263


In this paper it is shown that the Blazhko Effect may result from a near-resonant type of double-mode pulsation, where two periodic oscillations with slightly different frequencies gradually slip in phase by one pulsation cycle every Blazhko cycle, producing a beat frequency type of modulation. One of the oscillations is strongly non-sinusoidal while the other is not. This paper extends previous work on this hypothesis by developing a simple model that can accurately reproduce several important features found in Kepler data for RR Lyr, including the pulsation waveform, the upper and lower Blazhko envelope functions and the motion, disappearance and reappearance of the bump feature. This model is consistent with the fact that the triplet peaks in the spectra for most RR Lyrae stars have a larger peak on the higher frequency side. The current model is related to the hybrid mode model described in a previous paper. The motion and disappearance of the bump feature are shown to be an illusion, just an artifact of combining the two oscillations.

Read this paper on arXiv…

P. Bryant
Mon, 4 Aug 14
8/40

Comments: N/A