J/A+A/608/A63ivo://CDS.VizieR/J/A+A/608/A63doi:10.26093/cds/vizier.36080063CDSPerger M.Ribas I.Damasso M.Morales J.C.Affer L.,Suarez Mascareno A.Micela G.Maldonado J.Gonzalez Hernandez J.I.,Rebolo R.Scandariato G.Leto G.Zanmar Sanchez R.Benatti S.,Bignamini A.Borsa F.Carbognani A.Claudi R.Desidera S.Esposito M.,Lafarga M.Martinez Fiorenzano A.F.Herrero E.Molinari E.,Nascimbeni V.Pagano I.Pedani M.Poretti E.Rainer M.Rosich A.,Sozzetti A.Toledo-Padron B.2017-12-14T06:32:18Z2017-12-07T11:56:05ZCDS support team

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

cds-question@unistra.frmultiple-starssolar-system-planetsradial-velocityspectroscopyShort- to mid-term magnetic phenomena on the stellar surface of M-type stars can resemble the effects of planets in radial velocity data, and may also hide them. We analyze 145 spectroscopic HARPS-N observations of GJ 3942 taken over the past five years and additional photometry in order to disentangle stellar activity effects from genuine Doppler signals as a result of the orbital motion of the star around the common barycenter with its planet. To achieve this, we use the common methods of pre-whitening, and treat the correlated red noise by a first-order moving average term and by Gaussian-process regression following an MCMC analysis. We identify the rotational period of the star at 16.3-days and discover a new super-Earth, GJ 3942b, with an orbital period of 6.9-days and a minimum mass of 7.1M_Earth_. An additional signal in the periodogram of the residuals is present, but at this point we cannot claim with sufficient significance that it is related to a second planet. If confirmed, this planet candidate would have a minimum mass of 6.3M_Earth_ and a period of 10.4-days, which might indicate a 3:2 mean-motion resonance with the inner planet.2017A&A...608A..63Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/608/A63CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/593/A117 : GJ 3998 RVs, S and Halpha indexes (Affer+, 2016)J/A+A/598/A26 : HADES RV Programme with HARPS-N at TNG. II. (Perger+, 2017)J/A+A/605/A92 : GJ 625 HARPS-N data (Suarez Mascareno+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/608/A63https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/608/A63http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/608/A63https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/608/A63https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/608/A63http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/608/A63GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/608/A63/table9Data of 145 observations of GJ 3942e_SS index errorstat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBarycentric Julian date (BJD-2456000)dtime.epochdoubleRVT? Relative radial velocity from TERRA pipeline (second fiber drifts already included)m/sphys.veloc;pos.heliocentricfloatnullablee_RVT? Radial velocity error from TERRAm/sstat.errorfloatnullableRVYRadial velocity from DRS pipelinem/sphys.veloc;pos.heliocentricdoublee_RVYRadial velocity error from DRSm/sstat.errorfloatdriftInstrumental RV drift of the observationm/sarith.ratefloate_driftInstrumental RV drift errorm/sstat.errorfloatSNRsignal-to-noise-ratio of order 46stat.snrfloatSS index from CaII H and K linesmeta.code;spect.indexfloatHalphaHalpha indexspect.index;em.line.Halphafloate_HalphaHalpha index errorstat.errorfloatNotesNotes (1)meta.notechar