This simulator allows the user to change key paramatersfor the system such as the sizes and temperatures for the stars, and the orbital inclination. This simulation is only for mainsequence stars. This can result from previous episodes of mass transfer in which the initially more massive component has transfered mass to the initially less massive component. By obtaining data during primary and secondard eclipses we may determine times of minimum light and derive values for orbital periods. Changes in orbital periods can be associated with mass transfer events between the components, elliptical orbits, or third bodies in the system.
Massive systems can even exhibit relativistic effects.
Complete light curves can be used for detailed analysis to infer important physical properties of the eclipsing systems. Z Dra Z Dra is a poorly studied close binary system with a 1.3 day period. The primary visual eclipses are approximately 2.5 magnitudes deep and have been monitored by visual observers for many decades. Because of its high northern declination this system has a rather long observing season in mid-northern latitudes. The system is apparently demonstrating interaction effects and has well documented period changes.