Changes in the Light Curves of Short-Period W Ursae Majoris Binaries: Program Summary

Abstract We are observing and analyzing changes in the light curves of a few W Ursae Majoris binaries. This paper summarizes the objectives of our program and the rationale behind our choice of stars and observational strategy. It also describes, briefly, our approach to the seasonal optimization of our reductions, and our two primary analytic approaches (phase-bin and Wilson-Devinney). 1. Program objectives The W UMa stars, overcontact binaries of late spectral type, are fascinating laboratories for understanding stellar structure and evolution. They typically consist of two stars of very different masses in physical contact, with mass ratios higher than ten-to-one in some cases. Despite nearly forty years of research on these stars, we still do not understand the details of their internal structure. New three-dimensional modeling codes are being developed that will enable researchers to make progress in understanding both the internal structure and evolution of these stars. Developing and testing these models fully will require observations of a magnitude heretofore unseen