부산대학교 도서관

The California-Kepler Survey (CKS) catalog contains precise stellar andplanetary properties for the \Kepler\ planet candidates, including systems withmultiple detected transiting planets ("multis") and systems with just onedetected transiting planet ("singles," although additional planets couldexist). We compared the stellar and planetary properties of the multis andsingles in a homogenous subset of the full CKS-Gaia catalog. We found thatsub-Neptune sized singles and multis do not differ in their stellar propertiesor planet radii. In particular: (1.) The distributions of stellar properties$M_\star$, [Fe/H], and $v\mathrm{sin}i$ for the Kepler sub Neptune-sizedsingles and multis are statistically indistinguishable. (2.) The radiusdistributions of the sub-Neptune sized singles and multis with $P > 3$ days areindistinguishable, and both have a valley at $\sim1.8~R_\oplus$. However, thereare significantly more detected short-period ($P < 3$ days), sub-Neptune sizedsingles than multis. The similarity of the host star properties, planet radii,and radius valley for singles and multis suggests a common origin. The similarradius valley, which is likely sculpted by photo-evaporation from the host starwithin the first 100 Myr, suggests that planets in both singles and multisspend much of the first 100 Myr near their present, close-in locations. Oneexplanation that is consistent with the similar fundamental properties ofsingles and multis is that many of the singles are members of multi-planetsystems that underwent planet-planet scattering.