Elemental Abundances of Kepler Objects of Interest in APOGEE. I. Two Distinct Orbital Period Regimes Inferred from Host Star Iron Abundances
AuthorWilson, Robert F.
Majewski, Steven R.
Prieto, Carlos Allende
Stassun, Keivan G.
Skrutskie, Michael F.
García-Hernández, D. A.
AffiliationUniv Arizona, Steward Observ
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationElemental Abundances of Kepler Objects of Interest in APOGEE. I. Two Distinct Orbital Period Regimes Inferred from Host Star Iron Abundances 2018, 155 (2):68 The Astronomical Journal
JournalThe Astronomical Journal
Rights© 2018. The American Astronomical Society. All rights reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractThe Apache Point Observatory Galactic Evolution Experiment (APOGEE) has observed similar to 600 transiting exoplanets and exoplanet candidates from Kepler (Kepler Objects of Interest, KOIs), most with >= 18 epochs. The combined multi-epoch spectra are of high signal-to-noise ratio (typically >= 100) and yield precise stellar parameters and chemical abundances. We first confirm the ability of the APOGEE abundance pipeline, ASPCAP, to derive reliable [Fe/H] and effective temperatures for FGK dwarf stars-the primary Kepler host stellar type-by comparing the ASPCAP-derived stellar parameters with those from independent high-resolution spectroscopic characterizations for 221 dwarf stars in the literature. With a sample of 282 close-in (P < 100 days) KOIs observed in the APOGEE KOI goal program, we find a correlation between orbital period and host star [Fe/H] characterized by a critical period, P-crit = 8.3(-4.1)(+0.1) days, below which small exoplanets orbit statistically more metal-enriched host stars. This effect may trace a metallicity dependence of the protoplanetary disk inner radius at the time of planet formation or may be a result of rocky planet ingestion driven by inward planetary migration. We also consider that this may trace a metallicity dependence of the dust sublimation radius, but we find no statistically significant correlation with host T-eff and orbital period to support such a claim.
VersionFinal published version
SponsorsNational Science Foundation [AST-1616636]; National Aeronautics and Space Administration [16-XRP16_2-0004]; Ramon y Cajal fellowship [RYC-2013-14182]; Spanish Ministry of Economy and Competitiveness (MINECO) [AYA-2014-58082-P]; Alfred P. Sloan Foundation; U.S. Department of Energy Office of Science; Center for High-Performance Computing at the University of Utah