CaltechAUTHORS
Published June 2022 | Version Published + Accepted Version
Journal Article Open

Scaling K2. V. Statistical Validation of 60 New Exoplanets From K2 Campaigns 2–18

Creators

  • 1. ROR icon NASA Exoplanet Science Institute
  • 2. ROR icon California Institute of Technology
  • 3. ROR icon University of Arizona
  • 4. ROR icon University of Southern California
  • 5. ROR icon Bay Area Environmental Research Institute
  • 6. ROR icon Ames Research Center
  • 7. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 8. ROR icon The University of Texas at Austin
  • 9. ROR icon University of California, Berkeley
  • 10. ROR icon NOIRLab
  • 11. ROR icon University of Southern Queensland
  • 12. ROR icon University of Tokyo
  • 13. ROR icon Stephen F. Austin State University
  • 14. ROR icon Stanford University
  • 15. ROR icon University of Notre Dame
  • 16. ROR icon University of Wisconsin–Stout
  • 17. ROR icon College of the Canyons
  • 18. ROR icon Rhode Island College
  • 19. ROR icon University of California, Santa Cruz
  • 20. ROR icon University of California, Davis
  • 21. ROR icon Astrobiology Center
  • 22. ROR icon National Astronomical Observatory of Japan
  • 23. ROR icon The Graduate University for Advanced Studies, SOKENDAI
  • 24. ROR icon Goddard Space Flight Center
  • 25. ROR icon University of Maryland, Baltimore County
  • 26. ROR icon University of Kansas
  • 27. ROR icon University of Chicago
  • 28. ROR icon Adler Planetarium
  • 29. ROR icon University of Geneva
  • 30. ROR icon University of California, Los Angeles

Abstract

The NASA K2 mission, salvaged from the hardware failures of the Kepler telescope, has continued Kepler's planet-hunting success. It has revealed nearly 500 transiting planets around the ecliptic plane, many of which are the subject of further study, and over 1000 additional candidates. Here we present the results of an ongoing project to follow-up and statistically validate new K2 planets, in particular to identify promising new targets for further characterization. By analyzing the reconnaissance spectra, high-resolution imaging, centroid variations, and statistical likelihood of the signals of 91 candidates, we validate 60 new planets in 46 systems. These include a number of planets amenable to transmission spectroscopy (K2-384 f, K2-387 b, K2-390 b, K2-403 b, and K2-398 c), emission spectroscopy (K2-371 b, K2-370 b, and K2-399 b), and both (K2-405 b and K2-406 b); several systems with planets in or close to mean motion resonances (K2-381 and K2-398) including a compact, TRAPPIST-1-like system of five small planets orbiting a mid-M dwarf (K2-384); an ultra-short-period sub-Saturn in the hot Saturn desert (K2-399 b); and a super-Earth orbiting a moderately bright (V = 11.93), metal-poor ([Fe/H] = −0.579 ± 0.080) host star (K2-408 b). In total we validate planets around four F stars, 26 G stars, 13 K stars, and three M dwarfs. In addition, we provide a list of 37 vetted planet candidates that should be prioritized for future follow-up observation in order to be confirmed or validated.

Additional Information

© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2021 December 21; revised 2022 February 1; accepted 2022 February 8; published 2022 May 9. The analyses 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 publication makes use of data products collected by the Kepler mission and obtained from the MAST data archive at the Space Telescope Science Institute (STScI); the K2SFF apertures can be accessed via https://doi.org/10.17909/T9BC75, and the K2 target pixel files via https://doi.org/10.17909/T9K30X. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS526555. Support to MAST for these data is provided by the NASA Office of Space Science via grant NAG57584 and by other grants and contracts. Funding for the Kepler mission was provided by the NASA Science Mission Directorate. This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. This data set is made available by the Infrared Science Archive (IRSA) at IPAC, which is operated by the California Institute of Technology under contract with the National Aeronautics and Space Administration. The specific data products can be accessed via https://doi.org/10.26131/IRSA2. Funding for this work for C.H. is provided by grant No. 80NSSC20K0874, through NASA ROSES. M.T. is supported by JSPS KAKENHI grant Nos. 18H05442, 15H02063, and 22000005. Support for this work was provided by NASA through the NASA Hubble Fellowship grant #51497.001 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. The material is based upon work supported by NASA under award number 80GSFC21M0002 and by the GSFC Sellers Exoplanet Environments Collaboration (SEEC), which is funded by the NASA Planetary Science Divisions Internal Scientist Funding Mode. The observations in the paper made use of the NN-EXPLORE Exoplanet and Stellar Speckle Imager (NESSI). NESSI was funded by the NASA Exoplanet Exploration Program and the NASA Ames Research Center. NESSI was built at the Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. The authors are honored to be permitted to conduct observations on Iolkam Du'ag (Kitt Peak), a mountain within the Tohono O'odham Nation with particular significance to the Tohono O'odham people. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC,https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This work made use of the gaia-kepler.fun crossmatch database created by Megan Bedell. Software: EVEREST (Luger et al. 2016, 2018), TERRA (Petigura et al. 2013), EDI-Vetter (Zink et al. 2020a), K2SFF (Vanderburg & Johnson 2014), PyMC3 (Salvatier et al. 2015), Exoplanet (Foreman-Mackey et al. 2019), RoboVetter (Thompson et al. 2018), batman Kreidberg (2015), emcee (Foreman-Mackey et al. 2013).

Attached Files

Published - Christiansen_2022_AJ_163_244.pdf

Accepted Version - 2203.02087.pdf

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Additional details

Identifiers

Eprint ID
115795
Resolver ID
CaltechAUTHORS:20220722-769478000

Related works

Describes
https://arxiv.org/abs/2203.02087 (URL)
10.17909/T9BC75 (DOI)
10.17909/T9K30X (DOI)
10.26131/IRSA2 (DOI)

Funding

NASA/JPL/Caltech
NASA
NAS5-26555
NASA
NAG57584
NASA
80NSSC20K0874
Japan Society for the Promotion of Science (JSPS)
18H05442
Japan Society for the Promotion of Science (JSPS)
15H02063
Japan Society for the Promotion of Science (JSPS)
22000005
NASA Hubble Fellowship
51497.001
NASA
80GSFC21M0002
NASA Ames Research Center
Gaia Multilateral Agreement

Dates

Created
2022-07-26
Created from EPrint's datestamp field
Updated
2022-07-26
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Astronomy Department, Infrared Processing and Analysis Center (IPAC)