학술논문
197 CANDIDATES and 104 VALIDATED PLANETS in K2's FIRST FIVE FIELDS
Document Type
article
Author
Crossfield, IJM; Ciardi, DR; Petigura, EA; Sinukoff, E; Schlieder, JE; Howard, AW; Beichman, CA; Isaacson, H; Dressing, CD; Christiansen, JL; Fulton, BJ; Lépine, S; Weiss, L; Hirsch, L; Livingston, J; Baranec, C; Law, NM; Riddle, R; Ziegler, C; Howell, SB; Horch, E; Everett, M; Teske, J; Martinez, AO; Obermeier, C; Benneke, B; Scott, N; Deacon, N; Aller, KM; Hansen, BMS; Mancini, L; Ciceri, S; Brahm, R; Jordán, A; Knutson, HA; Henning, T; Bonnefoy, M; Liu, MC; Crepp, JR; Lothringer, J; Hinz, P; Bailey, V; Skemer, A; Defrere, D
Source
Astrophysical Journal, Supplement Series. 226(1)
Subject
Language
Abstract
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), false positives, and 63 remaining candidates. Our validated systems span a range of properties, with median values of RP= 2.3 R⊕, P = 8.6 days, Teff = 5300 K, and Kp = 12.7mag. 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 R⊕, Kp = 9-13 mag). Of particular interest are planets smaller than 2 R⊕, orbiting stars brighter than Kp = 11.5 mag, 5 receiving Earth-like irradiation levels, and several multi-planet systems - including 4 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 (8 R⊕ and/or with P