Sixty Validated Planets from K2 Campaigns 5-8

December 2018 • 2018AJ....156..277L

Authors • Livingston, John H. • Crossfield, Ian J. M. • Petigura, Erik A. • Gonzales, Erica J. • Ciardi, David R. • Beichman, Charles A. • Christiansen, Jessie L. • Dressing, Courtney D. • Henning, Thomas • Howard, Andrew W. • Isaacson, Howard • Fulton, Benjamin J. • Kosiarek, Molly • Schlieder, Joshua E. • Sinukoff, Evan • Tamura, Motohide

Abstract • We present a uniform analysis of 155 candidates from the second year of NASA’s K2 mission (Campaigns 5-8), yielding 60 statistically validated planets spanning a range of properties with median values of R p = 2.5 {R}\oplus , P = 7.1 days, T eq = 811 K, and J = 11.3 mag. The sample includes 24 planets in 11 multiplanetary systems, as well as 18 false positives and 77 remaining planet candidates. Of particular interest are 18 planets smaller than 2 {R}\oplus , five orbiting stars brighter than J = 10 mag, and a system of four small planets orbiting the solar-type star EPIC 212157262. We compute planetary transit parameters and false-positive probabilities using a robust statistical framework and present a complete analysis incorporating the results of an intensive campaign of high-resolution imaging and spectroscopic observations. This work brings the K2 yield to over 360 planets, and by extrapolation, we expect that K2 will have discovered ∼600 planets before the expected depletion of its onboard fuel in late 2018.


IPAC Authors


Jessie Christiansen

Associate Scientist


David Ciardi

Senior Scientist


Benjamin Fulton

Assistant Scientist