Eclipsing binaries, multiples and orbital period changes in SuperWASP
Stellar, Exoplanet and Galactic Science from Massive, High-precision Variability Surveys
Marcus Lohr
Open University
Andrew Norton
The Wide Angle Search for Planets (SuperWASP) is a whole-sky high-cadence optical survey which has searched for exoplanetary transit signatures since 2004. Its archive contains long-term light curves for some 30 million 8-15 V mag stars, making it a valuable serendipitous resource for variable star research. Here we present some key results from our ongoing project investigating SuperWASP archival evidence for eclipsing binaries, in particular those exhibiting orbital period variations. Having developed custom tools to measure periods precisely and detect period changes reliably, we have identified and explored a collection of 143 candidate eclipsing binaries near the short-period limit in the main sequence binary period distribution. Amongst these we have further identified a probable hierarchical triple containing an M+M dwarf contact binary, which exhibits dramatic sinusoidal period variations; and a new doubly-eclipsing quintuple of relevance for understanding the formation of multiple star systems. We have also discovered an eclipsing binary containing a delta Scuti pulsator, and new evidence for period change or stability in 12 post-common-envelope eclipsing binaries, which may support the existence of circumbinary planets in such systems. A large-scale search for period changes in some 14000 SuperWASP eclipsing binary candidates has also yielded numerous examples of sinusoidal period variation, suggestive of tertiary companions, and may allow us to estimate the frequency of triple systems amongst low-mass stars.
13:30 - 15:00