Kepler-223 (KOI-730, KIC 10227020) is a G8 star with an extrasolar planetary system discovered by the Kepler mission. Studies indicate that the Kepler-223 star system consists of 4 planets orbiting the star.

Planetary system

The Kepler-223 planetary system
Companion (in order from star)MassSemimajor axis (AU)Orbital period (days)EccentricityInclinationRadius
b7.38453 R🜨
c9.84563.4 R🜨
d14.78875.2 R🜨
e19.72574.6 R🜨

The confirmed planetary system was first detected by the Kepler mission, and contains four planets. This system was initially believed to contain two co-orbital planets orbiting the star at approximately the same orbital distance every 9.8 days, with one permanently locked 60° behind the other in one of the two Trojan Lagrangian points. The two co-orbital planets were thought to be locked in mean motion resonances with the other two planets, creating an overall 6:4:4:3 resonance. This would have been the first known example of co-orbital planets.

However, follow-up study of the system revealed that an alternative configuration, with the four planets having orbital periods in the ratio 8:6:4:3 is better supported by the data. This configuration does not contain co-orbital planets, and has been confirmed by further observations. It represents the first confirmed 4-body orbital resonance.

The radii are 3.0, 3.4, 5.2, and 4.6 Earth radii, and the orbital periods are 7.3845, 9.8456, 14.7887 and 19.7257 days, respectively.

  • Kepler-223 6:4:4:3 orbital ratios
  • Kepler-223 8:6:4:3 orbital ratios

External links

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  • 2MASS Catalog