THE GDDSYN LIGHT-CURVE SYNTHESIS METHOD

We present a close binary system light curve synthesis algorithm called geodesic distribution binary synthesis (GDDSYN), which uses a novel surface element distribution and partial visibility computational scheme for the Roche model. The surface element distribution, based on the geodesic sphere, is well suited to maximum entropy imaging of surface features on eclipsing binaries. It allows the fitting of spot distributions which are less sensitive to observational errors than schemes which have too many low weight surface elements. The algorithm for computation of surface element visibility is based on techniques used in computer graphics, and is shown to be more accurate and faster than the Wilson-Devinney code. Light curves produced with GDDSYN are at least as accurate as those of the WD code, and in addition the light curve of each individual surface element is accurately computed to form the kernel needed for surface feature imaging. Examples and numerical tests have been computed.