Dr. Paczynski and collaborators will continue and expand the very successful Optical Gravitational Lensing Experiment (OGLE) to monitor millions of stars towards the Galactic Bulge and the Magellanic Clouds, with the goal of detecting and analyzing gravitational microlensing events. The collaborative project involves astronomers at the Warsaw University Observatory and their 1.3-meter telescope at Las Campanas Observatory in Chile. They will upgrade the CCD camera to install an 8K x 8K mosaic and will implement image subtraction software in the data flow. These improvements will increase the data rate, and microlensing detections, by an order of magnitude, to more than 500 events per year, and increase the accuracy of the photometry by a factor of at least two. The OGLE project uses standard BVI photometric bandpasses, and yields vast numbers of variable stars which can be analyzed for a variety of astrophysical projects. Of particular interest are issues in galactic structure and stellar populations such as a determination of the optical depth to microlensing events to verify models of the mass distribution in the inner galaxy, and the calibration of the extragalactic distance scale. The OGLE project makes data available to the public as soon as is practically feasible, to maximize the science to come from the survey by themselves and others.
