Abstract

mong more than 277 extra-solar planets discovered since 1995, the 42 or so that transit their host stars (of which 15 have been found by the SuperWASP project) are highly prized. Their radii and masses can be determined unambiguously from their light curves and reflex radial-velocity variations. With the help of planetary structural models, we gain important insights into their interior structures. Their host-star properties and orbital elements offer clues to their formation and subsequent evolution. We can measure the drop in thermal-infrared radiation as they pass behind their host stars, giving us a glimpse of the thermal structure of their upper atmospheres. Their atmospheric transmission spectra probe their atmospheric chemistry.

In this colloquium I’ll review what’s been happening in exoplanetary science over the last few years, and present the story of how the UK Wide-Angle Search for Planets (WASP) evolved from small beginnings into the world’s most ambitious and successful survey for bright transiting planets. I’ll describe the latest batch of ten WASP planets found since Christmas, and discuss what we are learning about them through ground and space-based follow-up programmes. I’ll end with an overview of present and future space missions that offer the prospect of characterising ice-giants and super-Earths in the same way.