Investigating light curve modulation due to the Blazhko effect using SuperWASP
Paul Greer
Open University
The Blazhko effect is a combination of amplitude modulation and frequency modulation, i.e. long term periodic variation in the amplitude and period of pulsations, in RR Lyrae and Delta Scuti stars. The Blazhko effect is named after S. Blazhko who discovered frequency modulation in 1907 while struggling to phase fold the light curve of RR Dra, followed by the discovery of the amplitude modulation of RR Lyrae itself by Shipley in 1916 (Szabo, 2013, and references therein). Despite being discovered over 100 years ago the physical cause of these modulations has not been explained. Current models range from atmospheric shock waves (Gillet & Folkin, 2014) to resonances between pulsation modes (Kolenberg & McWilliam, 2011) and non-resonance beat-modes (Bryant, 2014). Data from the SuperWASP archive can be used to identify potentially thousands of Blazhko effect RR Lyrae stars. With such a large sample of newly identified Blazhko effect RR Lyrae stars, we anticipate searching for correlations between characteristic parameters and dynamics that may help to provide an explanation for the phenomenon.