J/A+A/612/A95ivo://CDS.VizieR/J/A+A/612/A95doi:10.26093/cds/vizier.36120095CDSBarragan O.Gandolfi D.Dai F.Livingston J.Persson C.M.Hirano T.,Narita N.Csizmadia Sz.Winn J.N.Nespral D.Prieto-Arranz J.,Smith A.M.S.Nowak G.Albrecht S.Antoniciello G.Bo Justesen A.,Cabrera J.Cochran W.D.Deeg H..Eigmuller P.Endl M.Erikson A.,Fridlund M.Fukui A.Grziwa S.Guenther E.Hatzes A.P.Hidalgo D.,Johnson M.C.Korth J.Palle E.Patzold M.Rauer H.Tanaka Y.,Van Eylen V.2018-05-16T07:19:03Z2018-05-04T09:47:47ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frmultiple-starsk-starssolar-system-planetsphotometryradial-velocityWe report on the discovery of K2-141 b (EPIC 246393474 b), an ultra-short-period super-Earth on a 6.7-hour orbit transiting an active K7 V star based on data from K2 campaign 12. We confirmed the planet's existence and measured its mass with a series of follow-up observations: seeing-limited MuSCAT imaging, NESSI high-resolution speckle observations, and FIES and HARPS high-precision radial-velocity monitoring. K2-141 b has a mass of 5.31+/-0.46M_{Earth}_ and radius of 1.54+0.10-0.09R_{Earth}_, yielding a mean density of 8.00^+1.83^_-1.45_g/cm^3^ and suggesting a rocky-iron composition. Models indicate that iron cannot exceed ~70% of the total mass. With an orbital period of only 6.7 hours, K2-141 b is the shortest-period planet known to date with a precisely determined mass.2018A&A...612A..95Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/612/A95CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/612/A95https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/612/A95http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/612/A95https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/612/A95https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/612/A95http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/612/A95GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/612/A95/rvharpsHARPS RV measurementsBJDTime (BJD-2450000)dtime.epochdoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRVRadial velocitykm/sphys.veloc;pos.heliocentricfloate_RVRadial velocity errorkm/sstat.errorfloatBISBisectorkm/sphys.velocfloatFWHMFull Width Half Maximumkm/sspect.line.widthfloatSS-indexspect.indexfloate_SS-index errorstat.errorfloatTexpExposure timestime.duration;obs.exposureintSNSignal-to-Noise at 5500{AA}stat.snrfloatJ/A+A/612/A95/rvfiesFIES RV measurementsBJDTime (BJD-2450000)dtime.epochdoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRVRadial velocitykm/sphys.veloc;pos.heliocentricfloate_RVRadial velocity errorkm/sstat.errorfloatTexpExposure timestime.duration;obs.exposureintSNSignal-to-Noise at 5500{AA}stat.snrfloatJ/A+A/612/A95/lck2K2 datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDTime (BJD-2450000)dtime.epochdoubleFluxNormalized stellar fluxphot.flux;arith.ratiodouble