Kepler-223b

Lore & Background

Kepler-223b was discovered by the Kepler mission as part of a system initially thought to contain two co-orbital planets locked in a Trojan configuration at a 9.8-day orbital distance. This interpretation would have made it the first known example of co-orbital planets. However, follow-up study revealed that an alternative configuration—with four planets having orbital periods in the ratio 8:6:4:3—was better supported by the data. This configuration, which does not include co-orbital planets, has been confirmed by further observations. Kepler-223b has a radius of 3.0 Earth radii and an orbital period of 7.3845 days.

Reader's Guide

Kepler-223b's significance lies in its role within the first confirmed four-body orbital resonance among exoplanets. The system's initial misinterpretation as containing co-orbital planets highlighted the challenges of interpreting transit data, while the subsequent resolution demonstrated the importance of follow-up studies in planetary system characterization. The 8:6:4:3 resonance chain involving Kepler-223b and its three companion planets represents a rare dynamical state, offering insights into planetary migration and orbital stability. This system serves as a benchmark for understanding multi-planet resonances and the processes that shape compact planetary architectures. The confirmed resonance also provides constraints on the formation and evolution of the system, as such configurations are thought to arise from convergent migration in a protoplanetary disk.

Did You Know?

• Its orbital period is 7.3845 days.
• The system was initially thought to contain co-orbital planets, but this was later ruled out.
• Kepler-223b is part of the first confirmed four-body orbital resonance, with periods in the ratio 8:6:4:3.