AAO Colloquium.

Wednesday, 29 September 2004 - 3:30 AAO Conference Room

Extrasolar Planets: The Next Decade

Paul Butler

ANU

The extraordinary growth in our knowledge of planetary systems over the past decade has been driven by the discovery of the first 127 planetary systems from precision Doppler surveys. Complementary detection techniques, including ground and space-based astrometric interferometry and direct imaging are a decade from producing results, while transit surveys and microlensing candidates are typically at distances of 500 to 5,000 parsecs, making follow-up problematic. Over the next decade precision Doppler surveys will continue as the primary driver for extrasolar planet studies. Within the last 3 years surveys have expanded to include essentially all 2,000 primary target stars within 50 parsecs. Current precision of 3 m/s is barely sufficient to detect jupiter-mass planets at 5 AU. Precision of 1 m/s would provide a 10-sigma "Jupiter detection" and a 3-sigma detection of a saturn-mass at 5 AU, sufficient to compare the architecture of the Solar System to other planetary systems. Precision of 1 m/s would allow the detection of neptune-mass planets at 0.5 AU, and Super-Earths (M < 10 Mearth) in small orbits. This level of sensitivity is comparible to the billion dollar Space Interferometry Mission. We are currently surveying 1,700 stars at the AAT, Keck, Magellan, and Lick telescopes. Our goal is to achieve precision of 1 m/s precision on the 200 nearest quiescent G/K dwarfs within 15 parsecs, using primarily Keck in the north and the AAT in the south. Within the next 10 years we expect to have the first estimate G/K dwarfs with saturn-to-jupiter-mass planets out to 5 AU to compare with the Solar System. We currently know that at least 10% of late F, G, and early K dwarfs have planets. With another decade of increasingly sensitive data we anticipate finding a much higher percentage of stars have planets.