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Free keywords:
Astrophysics, Earth and Planetary Astrophysics, astro-ph.EP
Abstract:
PLATO 2.0 has recently been selected for ESA's M3 launch opportunity
(2022/24). Providing accurate key planet parameters (radius, mass, density and
age) in statistical numbers, it addresses fundamental questions such as: How do
planetary systems form and evolve? Are there other systems with planets like
ours, including potentially habitable planets? The PLATO 2.0 instrument
consists of 34 small aperture telescopes (32 with 25 sec readout cadence and 2
with 2.5 sec candence) providing a wide field-of-view (2232 deg2) and a large
photometric magnitude range (4-16 mag). It focusses on bright (4-11 mag) stars
in wide fields to detect and characterize planets down to Earth-size by
photometric transits, whose masses can then be determined by ground-based
radial-velocity follow-up measurements. Asteroseismology will be performed for
these bright stars to obtain highly accurate stellar parameters, including
masses and ages. The combination of bright targets and asteroseismology results
in high accuracy for the bulk planet parameters: 2%, 4-10% and 10% for planet
radii, masses and ages, respectively. The planned baseline observing strategy
includes two long pointings (2-3 years) to detect and bulk characterize planets
reaching into the habitable zone (HZ) of solar-like stars and an additional
step-and-stare phase to cover in total about 50% of the sky. PLATO 2.0 will
observe up to 1,000,000 stars and detect and characterize hundreds of small
planets, and thousands of planets in the Neptune to gas giant regime out to the
HZ. It will therefore provide the first large-scale catalogue of bulk
characterized planets with accurate radii, masses, mean densities and ages.
This catalogue will include terrestrial planets at intermediate orbital
distances, where surface temperatures are moderate. Coverage of this parameter
range with statistical numbers of bulk characterized planets is unique to PLATO
2.0.
