This award will support the continuation of a longstanding program to observe mass-transfer close binary stars. Long-term observations of such systems are important for determination of the orbital period and for detecting changes in the period that result from angular momentum loss. These observations can also yield basic data on the mass ratio and the mass-radius relation of the secondary stars, which are important tests of stellar evolution theory.
The broader impact of the proposed activity will come from the involvement of the amateur astronomical community in the monitoring of cataclysmic variables. The program is also expected to produce valuable information on the space distribution and lifetimes of cataclysmic variables in the Milky Way, and on how close binary stars end their lives.