HR: 08:10h
AN: P51A-01 INVITED [PDF]
TI: Extrasolar Planets
AU: * Butler, P
EM: paul@dtm.ciw.edu
AF: Carnegie Institution, Department of Terrestrial Magnetism
5241 Broad Branch Road, NW, Washington, DC 20015 United States
AB:
None of the roughly one hundred hundred extrasolar planets found
to date closely resembles the Solar System. Unlike the Solar
System, most extrasolar planets are in eccentric orbits. The giant
planets in the Solar System all orbit beyond 5 AU, while the known
extrasolar planets (with one exception) all orbit within 4 AU,
with several in extraordinarily small orbits with periods of days
to weeks.
Current state-of-the-art technology can only detect giant planets,
with the most massive planets being the easiest to detect. Nonetheless
the planet mass function rises toward lower masses down to the limit
of detection incompleteness, below a jupiter-mass. There are almost
no planets more massive than 5 jupiter-masses though these would
be the easiest to detect. The planet bearing stars are significantly
enriched in elements heavier than hydrogen and helium relative to both
the Sun and nearby stars.
NASA, the European Space Agency, NSF, and the European Southern
Observatory are all focused on "next generation" planet detection
technologies including giant ground-based 30 and 100 meter telescopes
capable of directly imaging giant planets, space-based interferometers
apable of detecting terrestrial-size planets in earth-like orbits,
and space-based telescopes capable of directly imaging earth-like
planets and taking their spectra. The first of these next generation
instruments should be operating by the end of the decade, with
first results coming in around 2015.
The goal of our group is to survey all Sun-like stars out to
50 parsecs, a total of about 2,000 stars. At the time of this
writing (September 2003) we are surveying 1,700 of these stars
using the Lick 3-m (California), Keck 10-m (Hawaii), 3.9-m AAT
(Australia) and 6.5-m Magellan (Chile) telescopes. Recent
discoveries from our group include several systems of multiple
planets, the only known transit planet, and the first sub-saturn
mass companions, as well as two-thirds of all known extrasolar
planets.
Solar System analogs, Jupiter and Saturn--like planets orbiting
beyond 4 AU, have not yet been discovered. These elusive planets
will begin emerging from our existing surveys before the end of
this decade. By 2010 our surveys will provide a first planetary
census of nearby stars, allowing us to estimate the ubiquity of
planetary systems and of "Solar System" analogs, and thus put
the Solar System in a Galatic perspective for the first time.
DE: 7539 Stellar astronomy
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting