Astrometry and Exoplanet Characterization: Gaia and Its Pandora's Box

TL;DR

Gaia's all-sky astrometric survey will significantly advance exoplanet detection and characterization by complementing other methods, despite technical challenges in orbit determination.

Contribution

The paper discusses technical issues and potential synergies of Gaia astrometry with other planet detection techniques, highlighting preliminary results.

Findings

Gaia will monitor hundreds of thousands of stars within 200 pc.

Synergies between Gaia and other planet-finding methods can enhance exoplanet characterization.

Preliminary results demonstrate the potential of combined astrometric and other observational data.

Abstract

In its all-sky survey, Gaia will monitor astrometrically hundreds of thousands of main-sequence stars within $\approx200$ pc, looking for the presence of giant planetary companions within a few AUs from their host stars. Indeed, Gaia observations will have great impact is the astrophysics of planetary systems (e.g., Casertano et al. 2008), in particular when seen as a complement to other techniques for planet detection and characterization (e.g., Sozzetti 2011). In this paper, I briefly address some of the relevant technical issues associated with the precise and accurate determination of astrometric orbits of planetary systems using Gaia data. I then highlight some of the important synergies between Gaia high-precision astrometry and other ongoing and planned, indirect and direct planet-finding and characterization programs, both from the ground and in space, and over a broad range of wavelengths, providing preliminary results related to one specific example of such synergies.