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Scaling K2. III. Comparable Planet Occurrence in the FGK Samples of Campaign 5 and Kepler

Zink, Jon K. and Hardegree-Ullman, Kevin K. and Christiansen, Jessie L. and Petigura, Erik A. and Dressing, Courtney D. and Schlieder, Joshua E. and Ciardi, David R. and Crossfield, Ian J. M. (2020) Scaling K2. III. Comparable Planet Occurrence in the FGK Samples of Campaign 5 and Kepler. Astronomical Journal, 160 (2). Art. No. 94. ISSN 1538-3881. doi:10.3847/1538-3881/aba123.

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Using our K2 Campaign 5 fully automated planet-detection data set (43 planets), which has corresponding measures of completeness and reliability, we infer an underlying planet population model for the FGK dwarf sample (9257 stars). Implementing a broken power law for both the period and radius distributions, we find an overall planet occurrence of 1.00^(+1.07)_(−0.51) planets per star within a period range of 0.5–38 days. Making similar cuts and running a comparable analysis on the Kepler sample (2318 planets; 94,222 stars), we find an overall occurrence of 1.10 ± 0.05 planets per star. Since the Campaign 5 field is nearly 120 angular degrees away from the Kepler field, this occurrence similarity offers evidence that the Kepler sample may provide a good baseline for Galactic inferences. Furthermore, the Kepler stellar sample is metal-rich compared to the K2 Campaign 5 sample, so a finding of occurrence parity may reduce the role of metallicity in planet formation. However, a weak (1.5σ) difference, in agreement with metal-driven formation, is found when assuming the Kepler model power laws for the K2 Campaign 5 sample and optimizing only the planet occurrence factor. This weak trend indicates that further investigation of metallicity-dependent occurrence is warranted once a larger sample of uniformly vetted K2 planet candidates is made available.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Zink, Jon K.0000-0003-1848-2063
Hardegree-Ullman, Kevin K.0000-0003-3702-0382
Christiansen, Jessie L.0000-0002-8035-4778
Petigura, Erik A.0000-0003-0967-2893
Dressing, Courtney D.0000-0001-8189-0233
Schlieder, Joshua E.0000-0001-5347-7062
Ciardi, David R.0000-0002-5741-3047
Crossfield, Ian J. M.0000-0002-1835-1891
Additional Information:© 2020 The American Astronomical Society. Received 2020 April 29; revised 2020 June 26; accepted 2020 June 28; published 2020 July 31. The simulations described here were performed on the UCLA Hoffman2 shared computing cluster and using the resources provided by the Bhaumik Institute. This research has made use of the NASA Exoplanet Archive and the Exoplanet Follow-up Observation Program website, which are operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This paper includes data collected by the Kepler mission and obtained from the MAST data archive at the Space Telescope Science Institute (STScI). Funding for the Kepler mission is provided by the NASA Science Mission Directorate. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 526555. Facilities: Exoplanet Archive - , Kepler - .
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Subject Keywords:Exoplanet catalogs ; Dwarf stars
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: Exoplanet catalogs (488); Dwarf stars (2053)
Record Number:CaltechAUTHORS:20200803-104100873
Persistent URL:
Official Citation:Jon K. Zink et al 2020 AJ 160 94
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:104700
Deposited By: Tony Diaz
Deposited On:03 Aug 2020 17:48
Last Modified:16 Nov 2021 18:34

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