Reanalysis of archival data from NASA's Kepler Space Telescope has revealed a stunning truth about the KOI-134 system: two planets orbit their star in a highly unusual configuration, overturning the earlier conclusion that the system harbored no planets and opening fresh perspectives in planetary science.
The two planets—KOI-134 b and KOI-134 c—follow orbits inclined by about 15 degrees to each other and are locked in a 2:1 orbital resonance. Previously, KOI-134 b was flagged as a false positive by automated pipelines because of its large transit timing variations (TTV). A team led by Emma Nabbie at the University of Southern Queensland carefully re-examined the data, confirmed KOI-134 b as a warm Jupiter, and uncovered a previously unseen "sibling" planet, KOI-134 c, whose inclined orbit had prevented it from transiting from Kepler's viewpoint. The study shows that KOI-134 b's transits can arrive up to 20 hours early or late—a direct result of gravitational interaction between the two planets.
This discovery not only confirms a two-planet system in KOI-134 but also highlights its complex orbital dynamics. The planets' motion has been likened to "wooden horses on an old-fashioned carousel," vividly illustrating their independent orbital planes, mutual tilt, and resonant dance. Emma Nabbie remarked: "Such a compact multi-planet system that is distinctly non-coplanar, with significant orbital periods and planes tilted both forward and backward, is extremely rare and provides a crucial case for understanding planet formation and evolution." Precise measurements of mutual inclination, resonance, and TTVs allow deeper insight into the internal dynamics of planetary systems—observations that were previously rare due to technical limitations.
The results have been published in Nature Astronomy, based on Kepler observations and supported by collaboration with the University of Geneva, University of La Laguna, and other institutions. Once again, this finding demonstrates the enduring value of scientific data: even from a retired telescope, archived observations continue to yield breakthrough discoveries.
