Physical origin of the Blazhko effect

Determine the physical origin of the Blazhko effect—the long-term amplitude and phase variability observed in Blazhko RR Lyrae stars—as a mechanism underlying their pulsational modulation.

Background

The paper identifies the Blazhko effect as a prominent example of long-term amplitude and phase variations in pulsating stars. Although the phenomenon has been known for more than a century, its underlying physical mechanism remains unresolved.

The paper develops a Fourier framework for distinguishing observational signatures associated with modulation, linear beating, and non-linear coupling. These mechanisms can generate overlapping frequency patterns, making the unresolved physical interpretation of Blazhko variability a central broader problem in the study of pulsating stars. However, the paper does not claim to determine the fundamental physical origin of the Blazhko effect itself.