Kem Cook
Institute for Geophysics and Planetary Physics
Lawrence Livermore National Laboratory
Abstract:
Shortly after the first microlensing surveys were begun in the early 1990s, it was shown that it should be possible to detect planets orbiting the lens of a microlensing event. A planet could significantly modify the microlensing light curve with the duration depending upon its mass. This deviation would be days for Jupiter mass planets and hours for Earth mass planets. Almost immediately thereafter, the PLANET collaboration was formed to closely monitor microlensing events found by ongoing microlensing surveys. By enlisting telescopes around the world, PLANET could continuously monitor ongoing microlensing events for the evidence of planets. Other collaborations formed and after 8 years, there was a definitive exoplanet discovery made by the OGLE and MOA collaborations in 2003. To date, there have been four exoplanet discoveries made via microlensing, and one of these is of a 5.5 Earth-mass planet orbiting an M dwarf. Two of these exoplanets are sub-Neptune mass planets. I will review microlensing, these discoveries and their implications forextrasolar planetary systems, and the future of microlensing planet searches.