Properties and Occurrence Rates for Kepler Exoplanet Candidates as a Function of Host Star Metallicity from the DR25 Catalog
Abstract
Correlations between the occurrence rate of exoplanets and their host star properties provide important clues about the planet formation process. We studied the dependence of the observed properties of exoplanets (radius, mass, and orbital period) as a function of their host star metallicity. We analyzed the planetary radii and orbital periods of over 2800 Kepler candidates from the latest Kepler data release, DR25 (Q1–Q17), with revised planetary radii based on Gaia DR2 as a function of host star metallicity (from the Q1–Q17 (DR25) stellar and planet catalog). With a much larger sample and improved radius measurements, we are able to reconfirm previous results in the literature. We show that the average metallicity of the host star increases as the radius of the planet increases. We demonstrate this by first calculating the average host star metallicity for different radius bins and then supplementing these results by calculating the occurrence rate as a function of planetary radius and host star metallicity. We find a similar trend between host star metallicity and planet mass: the average host star metallicity increases with increasing planet mass. This trend, however, reverses for masses >4.0 M_J: host star metallicity drops with increasing planetary mass. We further examined the correlation between the host star metallicity and the orbital period of the planet. We find that for planets with orbital periods less than 10 days, the average metallicity of the host star is higher than that for planets with periods greater than 10 days.
Additional Information
© 2018 The American Astronomical Society. Received 2018 June 21; revised 2018 September 20; accepted 2018 September 20; published 2018 October 25. We thank the referee for insightful comments and suggestions that have led to the improvement of the final manuscript. CM acknowledges support from the Swiss National Science Foundation under grant BSSGI0_155816, "PlanetsInTime." Parts of this work have been carried out within the frame of the National Center for Competence in Research PlanetS, supported by the SNSF. 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 also made use of NASA's Astrophysics Data System Abstract Service and the SIMBAD database, operated at CDS, Strasbourg, France.Attached Files
Published - Narang_2018_AJ_156_221.pdf
Accepted Version - 1809.08385.pdf
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Additional details
- Eprint ID
- 90415
- Resolver ID
- CaltechAUTHORS:20181025-110845725
- BSSGI0_155816
- Swiss National Science Foundation (SNSF)
- Created
-
2018-10-25Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)