197 Candidates and 104 Validated Planets in K2’s First Five Fields
Ian J. M. Crossfield, David R. Ciardi, Erik A. Petigura, Evan Sinukoff, Joshua E. Schlieder, Andrew W. Howard, Charles A. Beichman, Howard Isaacson, Courtney D. Dressing, Jessie L. Christiansen, Benjamin J. Fulton, Sébastien Lépine, Lauren Weiss, Lea Hirsch, John Livingston, Christoph Baranec, Nicholas M. Law, Reed Riddle, Carl Ziegler, Steve B. Howell, Elliott Horch, Mark Everett, Johanna Teske, Arturo O. Martinez, Christian Obermeier, Björn Benneke, Nic Scott, Niall Deacon, Kimberly M. Aller, Brad M. S. Hansen, Luigi Mancini, Simona Ciceri, Rafael Brahm, Andrés Jordán, Heather A. Knutson, Thomas Henning, Michaël Bonnefoy, Michael C. Liu, Justin R. Crepp, Joshua Lothringer, Phil Hinz, Vanessa Bailey, Andrew Skemer, Denis Defrere
(Submitted on 18 Jul 2016)
We present 197 planet candidates discovered using data from the first year of the NASA K2 mission (Campaigns 0-4), along with the results of an intensive program of photometric analyses, stellar spectroscopy, high-resolution imaging, and statistical validation. We distill these candidates into sets of 104 validated planets (57 in multi-planet systems), 30 false positives, and 63 remaining candidates. Our validated systems span a range of properties, with median values of R_P = 2.3 R_E, P=8.6 d, Tef = 5300 K, and Kp=12.7 mag. Stellar spectroscopy provides precise stellar and planetary parameters for most of these systems. We show that K2 has increased by 30% the number of small planets known to orbit moderately bright stars (1-4 R_E, Kp=9-13 mag). Of particular interest are 37 planets smaller than 2 R_E, 15 orbiting stars brighter than Kp=11.5, five receiving Earth-like irradiation levels, and several multi-planet systems — including four planets orbiting the M dwarf K2-72 near mean-motion resonances. By quantifying the likelihood that each candidate is a planet we demonstrate that our candidate sample has an overall false positive rate of 15-30%, with rates substantially lower for small candidates (< 2 R_E) and larger for candidates with radii > 8 R_E and/or with P < 3 d. Extrapolation of the current planetary yield suggests that K2 will discover between 500-1000 planets in its planned four-year mission — assuming sufficient follow-up resources are available. Efficient observing and analysis, together with an organized and coherent follow-up strategy, is essential to maximize the efficacy of planet-validation efforts for K2, TESS, and future large-scale surveys.
Comments: ApJS accepted. 66 pages, 12 figures, 10 tables, 64 new planets. Data uploaded to this https URL
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1607.05263 [astro-ph.EP] (or arXiv:1607.05263v1 [astro-ph.EP] for this version)
Submission history
From: Ian Crossfield
[v1] Mon, 18 Jul 2016 19:59:53 GMT (910kb,D)
http://arxiv.org/abs/1607.05263
