CaltechAUTHORS
  A Caltech Library Service

The Effects of Stellar Companions on the Observed Transiting Exoplanet Radius Distribution

Teske, Johanna K. and Ciardi, David R. and Howell, Steve B. and Hirsch, Lea A. and Johnson, Rachel A. (2018) The Effects of Stellar Companions on the Observed Transiting Exoplanet Radius Distribution. Astronomical Journal, 156 (6). Art. No. 292. ISSN 1538-3881. http://resolver.caltech.edu/CaltechAUTHORS:20181212-125416718

[img] PDF - Published Version
See Usage Policy.

1715Kb
[img] PDF - Accepted Version
See Usage Policy.

679Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20181212-125416718

Abstract

Understanding the distribution and occurrence rate of small planets was a fundamental goal of the Kepler transiting exoplanet mission, and could be improved with K2 and Transiting Exoplanet Survey Satellite (TESS). Deriving accurate exoplanetary radii requires accurate measurements of the host star radii and the planetary transit depths, including accounting for any "third light" in the system due to nearby bound companions or background stars. High-resolution imaging of Kepler and K2 planet candidate hosts to detect very close (within ~0.”5) background or bound stellar companions has been crucial for both confirming the planetary nature of candidates, and the determination of accurate planetary radii and mean densities. Here we present an investigation of the effect of close companions, both detected and undetected, on the observed (raw count) exoplanet radius distribution. We demonstrate that the recently detected "gap" in the observed radius distribution (also seen in the completeness-corrected distribution) is fairly robust to undetected stellar companions, given that all of the systems in the sample have undergone some kind of vetting with high-resolution imaging. However, while the gap in the observed sample is not erased or shifted, it is partially filled in after accounting for possible undetected stellar companions. These findings have implications for the most likely core composition, and thus formation location, of super-Earth and sub-Neptune planets. Furthermore, we show that without high-resolution imaging of planet candidate host stars, the shape of the observed exoplanet radius distribution will be incorrectly inferred, for both Kepler- and TESS-detected systems.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.3847/1538-3881/aaed2dDOIArticle
https://arxiv.org/abs/1804.10170arXivDiscussion Paper
ORCID:
AuthorORCID
Ciardi, David R.0000-0002-5741-3047
Howell, Steve B.0000-0002-2532-2853
Hirsch, Lea A.0000-0001-8058-7443
Alternate Title:The Effects of Stellar Companions on Exoplanet Radius Distributions
Additional Information:© 2018 The American Astronomical Society. Received 2018 April 25; revised 2018 September 14; accepted 2018 October 24; published 2018 December 4. Support for this work was provided by NASA through Hubble Fellowship grant HST-HF2-51399.001 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. This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This research has made use of the Exoplanet Follow-up Observation Program website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. High-resolution images referenced in this work have been obtained at the WIYN, Gemini, Palomar, and Keck telescopes. We thank Elise Furlan for fruitful discussion and sharing information that enhanced the quality of this work, and Susan Mullally for clarifying how the Kepler PDC accounts for stellar companions in the calculation of planet radii. We thank the anonymous referee for their detailed comments that improved the quality of this paper. Software: astropy.
Group:Infrared Processing and Analysis Center (IPAC)
Funders:
Funding AgencyGrant Number
NASA Hubble FellowshipHST-HF2-51399.001
NASANAS5-26555
Subject Keywords:binaries: close – planets and satellites: detection – techniques: high angular resolution
Record Number:CaltechAUTHORS:20181212-125416718
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20181212-125416718
Official Citation:Johanna K. Teske et al 2018 AJ 156 292
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:91732
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:12 Dec 2018 21:06
Last Modified:12 Dec 2018 21:06

Repository Staff Only: item control page