For centuries people have wondered whether there are planets orbiting distant stars. Astronomers started to discover such “exoplanets” in the 1990s and have identified thousands since then. Advances in technology have revealed bizarre new worlds unlike anything in our Solar System, while also bringing us to the threshold of finding planets similar to Earth.

In this lecture, Josh Winn will explain why it took so long to find exoplanets, what new technologies were required, and what kinds of planetary systems have been found. He will review our knowledge of the properties of their orbits, and their host stars. Measurements of the orientation of the star's rotation axis, in particular, have revealed numerous surprises and have been the subject of creative theorizing. He will also discuss opportunities to improve our understanding with data from an upcoming NASA mission, the Transiting Exoplanet Survey Satellite.

Winn is an astronomer at Princeton University.  His group uses optical telescopes to study exoplanetary systems, especially those in which the star and planet eclipse one another.  His recent work focuses on the architecture of planetary systems: the sizes, shapes, and orientations of the orbits, and the stellar obliquity. He was a participating scientist in the NASA Kepler mission and is a co-investigator in the Transiting Exoplanet Survey Satellite, scheduled for launch in late 2017.