J/A+A/712/A213ivo://CDS.VizieR/J/A+A/712/A213CDSBarbato D.Pinamonti M.Sozzetti A.Desidera S.D'Orazi V.,Maldonado J.Biazzo K.Naponiello L.Lanza A.F.Bignamini A.,Bonomo A.S.Brogi M.Cabona L.Damasso M.Gratton R.Mancini L.,Mantovan G.Nardiello D.Rainer M.Guilluy G.Giacobbe P.Malavolta L.,Cosentino R.Boschin W.Claudi R.2026-08-24T07:47:22Z2026-08-24T08:46:20ZCDS support team

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

cds-question@unistra.frmultiple-starsexoplanetsradial-velocityvisible-astronomyThe astrometric measurements provided by the Gaia space mission represent a key advancement in the search and characterization of exoplanets, helping in particular to solve the mass degeneracy intrinsic to the radial velocity (RV) method. The fact that a fraction of astrophysical false positives contaminates the current catalog of astrometric candidate solutions requires an RV follow-up to validate and confirm such candidates. Within the GAPS programme, we have observed a selected sample of 14 stars having Gaia astrometric solutions compatible with the presence of a substellar companion. The immediate aim of this survey is to identify astrophysical false positives and provide the first RV validation and confirmation of the remaining candidates. We analysed data collected with the HARPS-N spectrograph to identify stellar binary systems from the spectral cross-correlation function profiles. The remaining astrometric candidates were characterized via Markov chain Monte Carlo analysis searching for the best-fit RV solution. Among the stars in our sample with astrometric candidate solutions, we identify 6 as originating from close binary companions mimicking the astrometric motion of distant substellar companions, from which we can estimate an updated value of 43_-11_^+13^% for the binary contamination fraction in the Gaia DR3 catalog of astrometric candidates. We validate and confirm the remaining 8 solutions, corresponding to giant and brown dwarf companions with minimum masses between 8 and 62M_Jup_ and semimajor axes between 0.76 and 1.42 au, providing the first RV characterization for 6 of these candidates and updated orbital solutions for 2 previously confirmed ones2026A&A...712A.213Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/712/A213CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/712/A213https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/712/A213http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/712/A213https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/712/A213https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/712/A213http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/712/A213GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/712/A213/stars (List of studied stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/712/A213/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/712/A213/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/712/A213/stars?GETtext/xml+votable180.050000true314.289333314.11638890.0055555555555555566/10356 10792 10969 12517 13171 21941 29625 44981https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/712/A213?format=asciiOpticaldefaultJ/A+A/712/A213/starsList of studied starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDEJ2000Simbad declination (J2000)pos.eq.dec;meta.mainVCShow the Radial Velocity curvesmeta.ref.urlcharStarHost star namemeta.id;meta.maincharRAJ2000Simbad right ascension (J2000)pos.eq.ra;meta.mainJ/A+A/712/A213/table1RV and activity indexes timeseriesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarHost star namemeta.id;meta.maincharBJDEpoch of measurementdtime.epochdoubleTexpExposure timestime.duration;obs.exposureintRVRadial Velocity valuekm/sphys.veloc;pos.heliocentricdoublee_RVRadial Velocity uncertaintykm/sstat.errorfloatFWHMFull width half maximumkm/sspect.line.widthfloatBISBisector inverse spankm/sphys.velocfloatSmwS-indexphot.flux;arith.ratiofloate_SmwS-index uncertaintystat.errorfloatHalphaHalpha indexspect.indexfloate_HalphaHalpha index uncertaintystat.error;spect.linefloatNaINaI indexmeta.code;spect.indexfloate_NaINaI index uncertaintystat.errorfloat