DISCOVERY AND VALIDATION OF A HIGH-DENSITY SUB-NEPTUNE FROM THE K2 MISSION
Jenkins, James S.
Soto, Maritza G.
Morzinski, Katie M.
Males, Jared R.
Close, Laird M.
AffiliationUniv Arizona, Steward Observ
Keywordsplanets and satellites: composition
planets and satellites: detection
planets and satellites: fundamental parameters
planets and satellites: terrestrial planets
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationDISCOVERY AND VALIDATION OF A HIGH-DENSITY SUB-NEPTUNE FROM THE K2 MISSION 2016, 830 (1):43 The Astrophysical Journal
JournalThe Astrophysical Journal
Rights© 2016. 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.
AbstractWe report the discovery of K2-56b, a high-density sub-Neptune exoplanet, made using photometry from Campaign 4 of the two-wheeled Kepler (K2) mission, ground-based radial velocity (RV) follow-up from HARPS and high-resolution lucky and adaptive optics imaging obtained using AstraLux and MagAO, respectively. The host star is a bright (V - 11.04, K-s - 9.37), slightly metal-poor ([Fe/H] - -0.15 +/- 0.05 dex) solar analogue located at 152.1(-7.4)(+9.7) pc from Earth, for which we find a radius of R-* = 0.928(-04040)(+0.055) and a mass of M-* = 0.961(-0.029)(+0.032) M-circle dot. A joint analysis of the K2 photometry and HARPS RVs reveal that the planet is in a approximate to 42 day orbit around its host star, has a radius of 2.23(011)(+0.14)R(circle plus), and a mass of 16.3(6.1)(+6.0) M-circle plus. Although the data at hand put the planet in the region of the massradius diagram where we could expect planets with a pure rock (i.e., magnesium silicate) composition using two-layer models (i.e., between rock/iron and rock/ice compositions), we discuss more realistic three-layer composition models which can explain the high density of the discovered exoplanet. The fact that the planet lies in the boundary between "possibly rocky" and "non-rocky" exoplanets makes it an interesting planet for future RV follow-up.
VersionFinal published version
SponsorsCONICYT-PCHA/Doctorado Nacional.; FONDECYT ; Ministry for the Economy, Development, and Tourism Programa Iniciativa Cientifica Milenio [IC 120009]; BASAL CATA [PFB-06]; NASA Science Mission directorate; ESO programmes [096.C-0499(A), 096.C-0417(A), 096.D-0402(A)]
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