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.
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