J/A+A/708/A218ivo://CDS.VizieR/J/A+A/708/A218CDSBouy H.Duchene G.Strampelli G.Aguilar J.Olivares J.Palau A.,Barrado D.Raymond S.N.Huelamo N.Tamura M.Bertin E.Brandner W.,Cuillandre J.-C.Galli P.A.B.Miret-Roig N.2026-04-08T11:55:33Z2026-04-08T12:54:39ZCDS support team

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

cds-question@unistra.frstellar-associationsbrown-dwarfsexoplanetsinfrared-photometryvisible-astronomystellar-massesFree-floating planetary mass objects -worlds that roam interstellar space untethered to a parent star-challenge conventional notions of planetary formation and migration, but also of star and brown dwarf formation. We focus on the multiplicity among free-floating planets. By virtue of their low binding energy (compared to other objects formed in these environments), these low-mass substellar binaries represent a most sensitive probe of the mechanisms at play during the star formation process. We use the Hubble Space Telescope and its Wide Field Camera 3 and the Very Large Telescope and its ERIS adaptive optics facility to search for visual companions among a sample of 77 objects members of the Upper Scorpius and Taurus young nearby associations with estimated masses in the range between approximately 6-66Mjup We report the discovery of one companion candidate around a Taurus member with a separation of 111.9+/-0.4mas, or ~18au assuming a distance of 160pc, with an estimated primary mass in the range between 3-6Mjup and a secondary mass between 2.6-5.2M_Jup_, depending on the assumed age. This corresponds to an overall binary fraction of 1.8^+2.6^_-1.3_% among low-mass brown dwarfs and free-floating planetary mass objects over the separation range >7au. Despite the limitations of small-number statistics and variations in spatial resolution and sensitivity, our results, combined with previous high-spatial-resolution surveys, suggest a notable difference in the multiplicity properties of objects below ~30-50Mjup between Upper Sco and Taurus. In Taurus, a binary fraction of 5.6^+3.2^_-2.3_% is found for objects with masses below 30Mjup, and of 7.8^+3.0^_-2.4_% for objects with masses below 50Mjup, whereas no binary were found among 80 objects over the matching luminosity range in Upper Sco, corresponding to an upper limit of >=1.2%. This difference may point to intrinsically distinct formation conditions, with warmer parental molecular clouds originally present in Upper Sco potentially inhibiting fragmentation into the lowest-mass brown dwarfs and free-floating planets compared to cooler environments such as Taurus.2026A&A...708A.218Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/708/A218CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/757/141 : Companion IR detection limits in young associationsJ/ApJ/788/40 : Late-type targets in Taurus, Cha I, and Upper ScoJ/A+A/667/A163 : Upper Scorpius and Ophiuchus members (Miret-Roig+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/708/A218https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/708/A218http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/708/A218https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/708/A218https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/708/A218http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/708/A218GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/708/A218/tablea1 (HST targets)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/708/A218/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/708/A218/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/708/A218/tablea1?GETtext/xml+votable180.050000true63.8114528.002430.005555555555555556Cone search capability for table J/A+A/708/A218/tablea2 (VLT targets)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/708/A218/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/708/A218/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/708/A218/tablea2?GETtext/xml+votable180.050000true243.58935-23.654090.005555555555555556Cone search capability for table J/A+A/708/A218/tablec1 (List of Taurus late type members observed at high spatial resolution)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/708/A218/tablec1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/708/A218/tablec1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/708/A218/tablec1?GETtext/xml+votable180.050000true70.4402223.03280.005555555555555556Cone search capability for table J/A+A/708/A218/tablec2 (List of Usco late type members observed at high spatial resolution)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/708/A218/tablec2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/708/A218/tablec2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/708/A218/tablec2?GETtext/xml+votable180.050000true239.23108-22.977880.0055555555555555564/2772 5/262 270 10747 11079 6/342 350 365 1029-1031 1033 1037 1039-1040 1042-1043 1047 1052 1054-1055 1061 1063 1069 1073-1075 1078-1079 1084 1114-1115 1159 1164 1168-1170 23533 23549 24188 24191 24201 24221 24262 24281 29320 30729 42909 42934 42942 42954 42956 42962 42969 42976 42979 42982 42985-42987 42994 43000 43002-43003 44292-44293 44304-44305 44309 44311 44314 44336 44341 44343 44368 44372 44376 44378-44379 44384-44386 44388-44390 44397 44400-44402 44404 444091.5062136169708525e-19 2.706461185444514e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/708/A218?format=asciiOpticalInfrareddefaultJ/A+A/708/A218/tablea1HST targetsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObjectObject designation (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainMass1Mass estimated assuming 3Myr in Taurus and 5Myr in Upper ScosolMassphys.massfloatMass2? Mass estimated assuming 10Myr in Upper ScosolMassphys.massfloatnullableimagPan-STARRS i magnitudemagphot.mag;em.opt.Ifloate_imagrms uncertainty on imagmagstat.error;phot.magfloatzmagPan-STARRS z magnitudemagphot.mag;em.opt.Ifloate_zmagrms uncertainty on zmagmagstat.error;phot.magfloatF814WHST WFC3 F814W magnitudemagphot.mag;em.opt.Ifloate_F814Wrms uncertainty on F814Wmagstat.errorfloatF850LPHST WFC3 F850LP magnitudemagphot.mag;em.opt.Ifloate_F850LPrms uncertainty on F850LPmagstat.errorfloatJmag? 2MASS J magnitudemagphot.mag;em.IR.Jfloatnullablee_Jmag? rms uncertainty on Jmagmagstat.error;phot.magfloatnullableAssoc[Taurus USco] Association it belongsmeta.id.parentcharJ/A+A/708/A218/tablea2VLT targetsMass5Estimated Mass at 5Myr (1)solMassphys.massfloatMass10Estimated Mass at 10Myr (1)solMassphys.massfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObjectObject designationmeta.id;meta.mainintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainimagPan-STARRS i magnitudemagphot.mag;em.opt.Ifloate_imagrms uncertainty on imagmagstat.error;phot.magfloatzmagPan-STARRS z magnitudemagphot.mag;em.opt.Ifloate_zmagrms uncertainty on zmagmagstat.error;phot.magfloatJmag2MASS J magnitudemagphot.mag;em.IR.Jfloate_Jmagrms uncertainty on Jmagmagstat.error;phot.magfloatstrehlStrehl ratiostat.fit.paramintJ/A+A/708/A218/tablec1List of Taurus late type members observed at high spatial resolutionrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject designationmeta.id;meta.maincharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainimag? Pan-STARRS i magnitudemagphot.mag;em.opt.Ifloatnullablee_imag? rms uncertainty on imagmagstat.error;phot.magfloatnullablezmag? Pan-STARRS z magnitudemagphot.mag;em.opt.Ifloatnullablee_zmag? rms uncertainty on zmagmagstat.error;phot.magfloatnullableSimbadNameSimbad column added by the CDSmeta.idcharnullableSpTypeSpectral typesrc.spTypecharr_SpTypeReference for the spectral type (G1)meta.ref;pos.framecharMultipleMultiple system?meta.codecharr_MultipleReference for multiplicity (G1)meta.ref;pos.framecharJ/A+A/708/A218/tablec2List of Usco late type members observed at high spatial resolutionSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameObject designationmeta.id;meta.maincharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainimagPan-STARRS i magnitudemagphot.mag;em.opt.Ifloate_imagrms uncertainty on imagmagstat.error;phot.magfloatzmagPan-STARRS z magnitudemagphot.mag;em.opt.Ifloate_zmagrms uncertainty on zmagmagstat.error;phot.magfloatSpTypeSpectral typesrc.spTypecharr_SpTypeReference for the spectral type (G1)meta.ref;pos.framecharMultipleMultiple system?meta.codecharr_MultipleReference for multiplicity (G1)meta.ref;pos.framechar