Extra-Solar Planets with GAIA

Abstract.

GAIA, like Hipparcos, is a global astrometric mission which will survey the sky several times during the 5 years of its nominal lifetime. GAIA is being actively studied by ESA as a possible candidate for the next Cornerstone-class mission to be launched around 2009 and possibly earlier.

Results from detailed simulations show that GAIA would detect giant planets (M$_p \sim$ M _J ) around normal stars up to a distance of $\sim 200$ pc. This horizon includes over 500,000 dwarf stars earlier than K5 to be screened for planets. The same simulations predict that the main orbital parameters (semi-major axis, eccentricity, period, and inclination) of a significant fraction of the detected planets should be measurable to better than 30% up to 200 pc.

Our results indicate that GAIA’s contribution would uniquely complement the expectations from other spectroscopic and astrometric surveys for ground breaking science in the fields of formation and evolution of planetary systems.