# On the Detection of Extrasolar Moons and Rings

## TL;DR

This paper reviews the methods and progress in detecting moons and rings around exoplanets, highlighting the current technological readiness and the absence of confirmed detections so far.

## Contribution

It provides a comprehensive overview of observational techniques and recent search efforts for exomoons and rings, emphasizing the near-maturity of the required technology.

## Key findings

- No confirmed exomoon or exoring detections yet
- Observational methods are approaching maturity
- Searches have been conducted using proposed techniques

## Abstract

Since the discovery of a planet transiting its host star in the year 2000, thousands of additional exoplanets and exoplanet candidates have been detected, mostly by NASA's Kepler space telescope. Some of them are almost as small as the Earth's moon. As the solar system is teeming with moons, more than a hundred of which are in orbit around the eight local planets, and with all of the local giant planets showing complex ring systems, astronomers have naturally started to search for moons and rings around exoplanets in the past few years. We here discuss the principles of the observational methods that have been proposed to find moons and rings beyond the solar system and we review the first searches. Though no exomoon or exoring has been unequivocally validated so far, theoretical and technological requirements are now on the verge of being mature for such discoveries.