Astronomy Colloquium / Spring 2008

April 9

Prof. Scott Gaudi

Ohio State

Microlensing Searches for Planets: Results and Future Prospects

Microlensing is unique among planet detection methods in that it is potentially sensitive to analogs of all the solar system planets except Mercury, as well as to free floating planets. I review the landscape of microlensing searches for extrasolar planets, beginning with an outline of the method itself, and continuing with a review of the results that have been obtained to date. Six planets have been detected with microlensing so far; I discuss what these detections have taught us about the frequency of terrestrial planets, giant planets, and solar system analogs. I then speculate on the expected returns of next-generation microlensing experiments both from the ground and from space. When combined with the results from other complementary surveys, next generation microlensing surveys can yield an accurate and complete census of the frequency and properties of planets, and in particular cool, low-mass terrestrial planets.