J/A+A/657/A68ivo://CDS.VizieR/J/A+A/657/A68doi:10.26093/cds/vizier.36570068CDSSilva T.A.Demangeon O.D.SBarros S.C.C.Armstrong D.J.Otegi J.F.,Bossini D.Delgado Mena E.Sousa S.G.Adibekyan V.Nielsen L.D.,Dorn C.Lillo-Box J.Santos N.C.Hoyer S.Stassun K.G.Almenara J.M.,Bayliss D.Barrado D.Boisse I.Brown D.J.A.Diaz R.F.Dumusque X.,Figueira P.Hadjigeorghiou A.Hojjatpanah S.Mousis O.Osborn A.,Santerne A.Strom P.A.Udry S.Wheatley P.J.2022-10-12T08:46:23Z2022-01-17T07:34:12ZCDS support team

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

cds-question@unistra.frmultiple-starsexoplanetschemical-abundancesradial-velocityphotometryvisible-astronomyMost of the currently known planets are small worlds with radii between that of the Earth and Neptune. The characterization of planets in this regime shows a large diversity in compositions and system architectures, with distributions hinting at a multitude of formation and evolution scenarios. However, many planetary populations, such as high-density planets, are significantly under-sampled limiting our understanding on planet formation and evolution. NCORES is a large observing program conducted on the HARPS high-resolution spectrograph which aims to confirm the planetary status and to measure the masses of small transiting planetary candidates detected by transit photometry surveys in order to constrain their internal composition.Methods.Using photometry from the K2 satellite and radial velocities measured with the HARPS and CORALIE spectrographs, we search for planets around the bright (Vmag=10) and slightly evolved Sun-like star HD 137496. We precisely estimate the stellar parameters, M*=1.035+/-0.022M_{sun}_, R*= 1.587+/-0.028R_{sun}_, Teff=5799+/-61K,together with the chemical composition (e.g. [Fe/H]=-0.027+/-0.040dex) of the slightly evolved star. We detect two planets orbiting HD 137496. The inner planet, HD 137496 b, is a super-Mercury (an Earth-sized planet with the density of Mercury) with a mass of Mb=4.04+/-0.55M_{sun}_), a radius of Rb=1.31^+0.06^_-0.05_R_{sun}_ and a density of {rho}b=10.49^+2.08^_-1.82_g/cm^3^. From interior modeling analysis we find that the planet is composed mainly of iron, with the core representing over 70% of the planet's mass (Mcore/Mtotal=0.73^+0.11^_-0.12_). The outer planet, HD 137496 c, is an eccentric (e=0.477+/-0.004), long period (P=479.9^+1.0^_-1.1_days) giant planet (Mc*sinic=7.66+/-0.11M_{Jup}_) for which we do not detect a transit. HD 137496 b is one of the few super-Mercuries detected to date. The accurate characterization reported here enhances its role as a key target to better understand the formation and evolution of planetary systems. The detection of an eccentric long period giant companion also reinforces the link between the presence of small transiting inner planets and long period gas giants.2022A&A...657A..68Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/657/A68CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/657/A68https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/657/A68http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/657/A68https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/657/A68https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/657/A68http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/657/A68GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/657/A68/rvHD 137496 radial velocities and stellar activity indicators measured with HARPS and CORALIE (table 1)RVRadial velocitym/sphys.veloc;pos.heliocentricdoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTimeTime of the measurement, UTC (BJD-2400000)dtime.epochdoublee_RVUncertainty on the radial velocity (1 sigma)m/sstat.errordoubleFWHMFull Width at Half Maximum (FWHM)m/sspect.line.widthdoublee_FWHMUncertainty on the FWHM (1 sigma)m/sstat.error;phys.angSizedoubleBisSpanBisector spanm/sphys.velocdoublee_BisSpanUncertainty on the bisector span (1 sigma)m/sstat.errordoubleContrastConstraststat.fit.paramdoublee_ContrastUncertainty on the contrast (1 sigma)stat.errordoubleHaH{alpha} indexspect.indexdoublee_HaUncertainty on the H{alpha} index (1 sigma)stat.errordoubleNaNa indexspect.indexdoublee_NaUncertainty on the Na index (1 sigma)stat.errordoubleCaCa indexspect.indexdoublee_Ca? Uncertainty on the Ca index (1 sigma)stat.errordoublenullableRHK? Activity index RHKphot.flux;arith.ratiodoublenullablee_RHK? Uncertainty on the activity index RHK (1 sigma)stat.errordoublenullableSMW? Mount Wilson S-indexphot.flux;arith.ratiodoublenullablee_SMW? Uncertainty on the Mount Wilson S-index (1 sigma)stat.errordoublenullableBERVBarycentric Earth Radial Velocitym/sphys.veloc;pos.barycenterdoubleInst[HARPS CORALIE] Instrument usedinstr.setupcharJ/A+A/657/A68/photomHD 137496 photometric data from K2 after PCA detrending and from the POLAR pipeline (table A1)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTimeTime of the measurement, UTC (BJD-2400000)dtime.epochdoubleFluxK2? Flux from the K2 PDCsap detrended lightcurvephot.flux.densitydoublenullablee_FluxK2? Error in the flux from the K2 PDCsap detrended lightcurvestat.errordoublenullableFluxPOLARFlux from the POLAR detrended lightcurvephot.flux.densitydoublee_FluxPOLARError in the flux from the POLAR detrended lightcurvestat.errordouble