Modeling of asymmetric light curves of eclipsing binaries on the Cyber 205 supercomputer

A major program at the University of Calgary's Rothney Astrophysical Observatory (RAO) is the study of eclipsing close-binary stars, which, because of circularization effects, are all cases of the restricted three-body problem. The physical properties of such systems are derived from modeling of the light and radial velocity curves. Uniqueness questions notwithstanding, careful use of the technique is found to yield reliable elements of the orbit and parameters of the component stars, even in the face of light curve perturbations. This work requires a greatly enlarged data base over previous work, and more complex modeling procedures, necessitating the use of a supercomputer. A version of the generalized synthetic light curve program of Wilson (1979) with star spot simulations has been adapted to and optimized for the University of Calgary's Cyber 205 supercomputer and further improvements are underway. With the use of personal computer graphics software, results have been transformed into three-dimensional, rotating models which help visualize the overcontact and perturbation conditions.