Gravitational Microlensing: A powerful method for the detection of extrasolar planets

by Joachim Wambsganss (Astronomisches Rechen-Institut (ARI) at Zentrum für Astronomie der Universität Heidelberg (ZAH))

Tuesday 31 May 2011, 13:15 → 14:15 Europe/Stockholm

FA32

After a short review on the different search methods for exoplanets, I will present and discuss the gravitational microlensing technique. The basics of the method and its current mode of operation will be explained as well as its advantages and disadvantages compared to other planet-search techniques. By now more than a dozen microlensing planets have been found, some of them with properties surprisingly similar to the solar system planets. A couple of them will be discussed in detail. The most interesting results so far: 1) low mass planets at a few AU ("cool Neptuns") are common, and 2) the very recent discovery of a large population of wide-separation or possibly free-floating "Jupiters". In a brief outlook, the immense potential of microlensing for good statistical inference on the Galactic population of exoplanets will be emphasized, as well as its sensitivity to low mass exoplanets and even exomoons.