Astrometric detection of exoplanets

TL;DR

This paper discusses how high-precision astrometry, especially via Gaia, enables the detection of thousands of exoplanets by measuring stellar positions with unprecedented accuracy, surpassing previous surveys.

Contribution

It introduces advanced astrometric techniques and evaluates Gaia's potential to detect exoplanets, highlighting its superior capabilities over past methods.

Findings

Gaia can measure star positions with 20 μas precision.

Expected discovery of over 10,000 exoplanets by Gaia.

Analysis of detection limits for astrometric exoplanet detection.

Abstract

As the most ancient branch of astronomy, astrometry has been developed for thousands of years. However, it has only recently become possible to utilize astrometry for the detection of exoplanets. Gaia, an astrometric surveyor of 1 billion stars, is capable of measuring the position of stars with a precision as high as 20 $\mu$as. Gaia is expected to discover more than 10,000 exoplanets by the end of its mission, surpassing the productivity of most exoplanet surveys. In this chapter, I will introduce different techniques used to achieve high-precision astrometry. Subsequently, I will explore how both relative and absolute astrometry can be employed to detect exoplanets. Finally, I will present the detection limit of the Gaia astrometric survey.