In Search of Exomoons

TL;DR

This paper reviews the theoretical background, detection methods, and initial observational results related to exomoons, aiming to understand their formation, evolution, and potential habitability in the context of exoplanet research.

Contribution

It provides a comprehensive overview of the current state of exomoon detection efforts, including theoretical insights, proposed methods, and initial observational findings.

Findings

Theoretical studies guide observational searches for exomoons.

Various detection methods have been proposed and evaluated.

Initial observational results are summarized with future prospects discussed.

Abstract

Two decades ago, astronomers began detecting planets orbiting stars other than our Sun, so-called exoplanets. Since that time, the rate of detections and the sensitivity to ever-smaller planets has improved dramatically with several Earth-sized planets now known. As our sensitivity dives into the terrestrial regime, increasingly the community has wondered if the moons of exoplanets may also be detectable, so-called "exomoons". Their detection represents an outstanding challenge in modern astronomy and would provide deep insights into the uniqueness of our Solar System and perhaps even expand the definition of habitability. Here, I will briefly review theoretical studies exploring the formation and evolution of exomoons, which serve to guide observational searches and provide testable hypotheses. Next, I will outline the different methods which have been proposed to accomplish this challenging feat and their respective merits. Finally, initial results from observational efforts will be summarized with a view to future prospects as well.