Lecture 46: ExoPlanets - Planets around Other Stars

Are there planets around other stars? Are there Earth-like planets around other stars? Do any of those harbor life? Intelligent life? We'd like to know the answers to all of these questions, and in recent years we've made great progress towards at least answering the first. To date, more than 200 planets have been found around other stars, most in the interstellar neighborhood of the Sun, but a few at great distance. This lecture reviews the search for ExoPlanets, discussing the successful Doppler Wobble, Transit, and Microlensing techniques. What we have found so far are very suprising systems, especially Jupiter-size or bigger planets orbiting very close (few hundredths of an AU) from their parent stars. The existance of a significant population of so-called "Hot Jupiters" may be telling us that planetary migration can be much more extreme that we saw in our own Solar System, or that these planetary system formed in a very different way than ours. It seems appropriate to end this class with more questions than answers, but that's where the science becomes most exciting. Recorded 2006 Dec 1 in 100 Stillman Hall on the Columbus campus of The Ohio State University.