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The Gaia Astrometric Survey A. Sozzetti INAF – Osservatorio Astronomico di Torino. 10 μ as Astrometry: 2012-2017. Gaia Project Status and Schedule. Now August 2012. Performance on red stars is 20%-30% better at bright mags. Gaia Discovery Space. 2-3 M J planets at
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The Gaia Astrometric Survey A. Sozzetti INAF – Osservatorio Astronomico di Torino
Gaia Project Status and Schedule Now August 2012
Gaia Discovery Space • 2-3 MJ planets at • 2<a<4 AU are detectable • out to~200 pc around • solar analogs • 2) Saturn-mass planets with • 1<a<4 AU are measurable • around nearby (<25 pc) • M dwarfs Critical assumption: σA ~ 15 μas (6<V<13) Sozzetti 2009
How Many Planets will Gaia find? Star counts (V<13), Fp(Mp,P), Gaia completeness limit Casertano, Lattanzi, Sozzetti et al. 2008 How Many Multiple-Planet Systems will Gaia find? Star counts (V<13), Fp,mult, Gaia detection limit Unbiased, magnitude-limited census of hundreds of thousands stars
The Gaia Legacy (1) How do Planet Properties and Frequencies Depend Upon the Characteristics of the Parent Stars (also, What is the Preferred Mechanism of Gas Giant Planet Formation?)? Johnson 2007 Sozzetti et al. 2009 ? Casertano et al. 2008 Gaia will test the fine structure of giant planet parameters distributions and frequencies, and investigate their possible changes as a function of stellar mass, metallicity, and age with unprecedented resolution 104 stars per 0.1 MSun bin!
The Gaia Legacy (2) How Do Dynamical Interactions Affect the Architecture of Planetary Systems? E.g., coplanarity tests will allow to determine the relative importance of many proposed mechanisms for eccentricity excitation in a statistical sense, not just on a star-by-star basis. • Interactions between a planet and the • gaseous/planetesimal disk? • Planet-planet resonant interactions? • Close encounters between planets? • d) Secular interactions with a companion star? Thommes & Lissauer 2003 Very strong impact on habitability studies too!
The Gaia Legacy (3) What Are the Phase Functions and Light Curves of Gas Giant Planets? Burrows et al. 2005 Gaia could provide important supplementary data to aid in the interpretation of direct detections of giant exoplanets both by helping to characterize their thermo-physical conditions and by determining the epoch and location of their maximum brightness.
The Gaia Legacy (4) Where Are the Earth-Like Planets, and What Are Their Characteristics? Nearby stars: THE targets. Kaltenegger et al. 2007 They must be studied as best as one can Gaia will provide important supplementary data for the optimization of the characterization of targets, e.g., by screening all stars within ~25 pc for Jupiter- and Saturn-sized planets out to several AUs. Neptune-mass (and smaller) planets will be detectable around thousands of M dwarfs
Gaia will derive the largest compilation of astrometric orbits of giant planets (in many cases signposts of more interesting systems!), unbiased across all spectral types and ages up to D~200 pc Get ready: Gaia data will start rolling in as early as ~2015 Gaia can crucially contribute to several aspects of planetary systems astrophysics (formation theories, dynamical evolution), in combination with present-day and future extrasolar planet search programs The Gaia community has already started coordinated efforts (GREAT) for the full exploitation of the science (including exoplanets) See Gaia in context as well as a synergy: it will improve your roadmapping exercise! Conclusions