Extra-solar planets observations: Towards "Exo-planetology"

It is now "Year 11" for extrasolar planet studies, and the frantic pace of progress shows no sign of slowing down. Recent landmarks since the last Cool Star meeting include the detection of planets of a few Earth masses by radial velocity and microlensing surveys, and the characterization of several hot gas giants caught transiting their host star. Transiting planets have served as a Rosetta Stone to connect the abstract language of exoplanet orbits to the detailed knowledge of solar system planets, providing an empirical foundation to the nascent field of "exo-planetology". Precise masses and radii are known for more than a dozen transiting gas giants, some discovered by wide-field photometric monitoring, others by radial velocity surveys. The atmosphere of the brightest of these planets has been observed with the Hubble and Spitzer space telescopes. The Corot satellite, launched on 26 December 2006, is expected to discover dozens of transiting planets, possibly including water-dominated planets and telluric planets.