The two main techniques for finding exoplanets, the Doppler and planetary transit methods, are both sensitive
primarily to close-in giant planets. In comparison, gravitational microlensing enables the detection of other
types of planets, such as Earth-mass planets at AU separations from their host stars. The gravitational microlensing
effect occurs when a stellar-mass object passes in the foreground of a distant observed star, located for example
in the Galactic Bulge. During the course of the passage the gravitational field of the object temporarily amplifies
the light from the background star. The structure of the measured light curve of such a microlensing event depends
on the nature of the lensing object. Usually the lens is just a single star or a binary star, but occasionally the
lens is found to be a star with one or more planets. In this seminar I will describe the technique, the planets
detected by it so far, and discuss its prospects for the future.
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