On the Relative Sizes of Planets within Kepler Multiple Candidate Systems

We present a study of the relative sizes of planets within the multiple candidate systems discovered with the Kepler mission. We have compared the size of each planet to the size of every other planet within a given planetary system after correcting the sample for detection and geometric biases. We find that for planet-pairs for which one or both objects is approximately Neptune-sized or larger, the larger planet is most often the planet with the longer period. No such size–location correlation is seen for pairs of planets when both planets are smaller than Neptune. Specifically, if at least one planet in a planet-pair has a radius of & 3R⊕, 68 ± 6% of the planet pairs have the inner planet smaller than the outer planet, while no preferred sequential ordering of the planets is observed if both planets in a pair are smaller than . 3R⊕. Subject headings: planetary systems