# Search for rings and satellites around the exoplanet CoRoT-9b using Spitzer photometry

## TL;DR

This study used Spitzer photometry to search for rings and satellites around exoplanet CoRoT-9b, setting upper limits on their sizes and orientations based on non-detections in two observed transits.

## Contribution

First constraints on the size and inclination of potential rings and satellites around CoRoT-9b using infrared photometry and transit analysis.

## Key findings

- Satellites larger than 2.5 Earth radii are excluded at 3-sigma.
- Rings with certain sizes and inclinations are ruled out.
- Ring inclination must be below 13° (silicate) or 3° (ice) for Roche limit extensions.

## Abstract

Using Spitzer photometry at 4.5 microns, we search for rings and satellites around the long period transiting planet CoRoT-9b. We observed two transits in 2010 and 2011. From their non-detection, we derive upper limits on the plausible physical characteristics of these objects in the planet environment. We show that a satellite larger than about 2.5 Earth radii is excluded at 3-$\sigma$ for a wide range of elongations at the two epochs of observations. Combining the two observations, we conclude that rings are excluded for a wide variety of sizes and inclination. We find that for a ring extending up to the Roche limit, its inclination angle from the edge-on configuration as seen from the Earth must be lower than 13{\deg} in the case of silicate composition and lower than 3{\deg} in the case of material with water ice density.