Evryscope is an array of twenty-four individual telescopes built by UNC and deployed on Cerro Tololo with the purpose of imaging the entire Southern sky once every two minutes. Now having operated for more than three years, the Evryscope has produced insurmountable data on most Southern targets brighter than 16th magnitude. Many of the helium-fusing hot subdwarf stars are members of post-common-envelope binaries with white dwarfs or low-mass stellar/substellar companions. These systems are typically bright with characteristically short periods, often exhibiting eclipses, ellipsoidal modulation, or a reflection effect. Evryscope is an unparalleled tool for studying these post-common-envelope systems in many interesting ways. While the raw light curves are noisy due to the small aperture size, phase folding the data over such a large number of orbital cycles produces high signal-to-noise light curves suitable for model fitting. Additionally, we can monitor small drifts or oscillations in the arrival times of photons which may reveal secular evolution of the binary, gravitational wave emission, or reflex motion due to circumbinary objects. Perhaps most exciting is our ability to detect previously-unknown variability in hot subdwarf systems. Here we present several years of Evryscope photometry and discuss our analyses of several interesting hot subdwarf binaries. This material is based in part upon work supported by the National Science Foundation under Grant No. AST-1812874.
American Astronomical Society Meeting Abstracts #233
- Pub Date:
- January 2019