Education
Are there planets around other stars? This lecture reviews the methods used to hunt for exoplanets and the results thus far. I will describe direct imaging methods, indirect methods relying on the gravitational influence of the planet on its parent star, planetary transits in which a planet blocks part of its parent star's light, and gravitational microlensing. There has been an explosion in our knowledge of planets around other stars, from little or nothing in the early 1990s to more than 400 planets around some 340-odd stars as of today. Recorded live on 2009 Nov 17 in Room 1005 Smith Laboratory on the Columbus campus of The Ohio State University.