Detection and Characterization of Planetary Systems with $\mu$as Astrometry

TL;DR

This review discusses the potential of micro-arcsecond astrometry for detecting and characterizing planetary systems, highlighting technical challenges and future observatories' capabilities to advance planetary science.

Contribution

It provides a comprehensive overview of past efforts, current challenges, and future prospects of astrometry in exoplanet detection and system characterization.

Findings

Astrometry has historically had limited utility but is poised for significant advancements.

Future micro-arcsecond astrometry can fully characterize multiple-planet systems.

Astrometry will complement other methods in planetary detection and analysis.

Abstract

Astrometry as a technique has so far proved of limited utility when employed as either a follow-up tool or to independently search for planetary mass companions orbiting nearby stars. However, this is bound to change during the next decade. In this review, I start by summarizing past and present efforts to detect planets via milli-arcsecond astrometry. Next, I provide an overview of the variety of technical, statistical, and astrophysical challenges that must be met by future ground-based and space-borne efforts in order to achieve the required degree of astrometric measurement precision. Then, I discuss the planet-finding capabilities of future astrometric observatories aiming at micro-arcsecond precision, with a particular focus on their ability to fully describe multiple-component systems. I conclude by putting astrometry in context, illustrating its potential for important contributions to planetary science, as a complement to other indirect and direct methods for the detection and characterization of planetary systems.