K2 star parameters from Gaia & LAMOST

DOI

Previous measurements of stellar properties for K2 stars in the Ecliptic Plane Input Catalog (EPIC) largely relied on photometry and proper motion measurements, with some added information from available spectra and parallaxes. Combining Gaia DR2 distances with spectroscopic measurements of effective temperatures, surface gravities, and metallicities from the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) DR5, we computed updated stellar radii and masses for 26838 K2 stars. For 195250 targets without a LAMOST spectrum, we derived stellar parameters using random forest regression on photometric colors trained on the LAMOST sample. In total, we measured spectral types, effective temperatures, surface gravities, metallicities, radii, and masses for 222088 A, F, G, K, and M-type K2 stars. With these new stellar radii, we performed a simple reanalysis of 299 confirmed and 517 candidate K2 planet radii from Campaigns 1-13, elucidating a distinct planet radius valley around 1.9R_{Earth}_, a feature thus far only conclusively identified with Kepler planets, and tentatively identified with K2 planets. These updated stellar parameters are a crucial step in the process toward computing K2 planet occurrence rates.

Cone search capability for table J/ApJS/247/28/table3 (Refined K2 planet parameters)

Cone search capability for table J/ApJS/247/28/table1 (K2 stellar parameters)

Identifier
DOI http://doi.org/10.26093/cds/vizier.22470028
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/ApJS/247/28
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/247/28
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/247/28
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/ApJS/247/28
Provenance
Creator Hardegree-Ullman K.K.; Zink J.K.; Christiansen J.L.; Dressing C.D.,Ciardi D.R.; Schlieder J.E.
Publisher CDS
Publication Year 2020
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Exoplanet Astronomy; Interdisciplinary Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy