J/AJ/169/116ivo://CDS.VizieR/J/AJ/169/116doi:10.26093/cds/vizier/be-59-3mCDSLiu R.Shao Z.Li Lu2026-07-02T11:45:19Z2025-12-11T09:36:36ZCDS support team

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

cds-question@unistra.frmultiple-starsstellar-massesopen-star-clustersphotometryvisible-astronomyinfrared-astronomyapparent-magnitudeAccurate determination of binary fractions (fb) and mass ratio (q) distributions is crucial for understanding the dynamical evolution of open clusters. We present an improved multiband fitting technique to enhance the analysis of binary properties. This approach enables an accurate photometric determination of fb and q distribution in a cluster. The detectable mass ratio can be down to the q_lim_, limited by the minimum stellar mass in theoretical models. First, we derived an empirical model for magnitudes of Gaia DR3 and 2MASS bands that match the photometry of single stars in the Pleiades. We then performed a multiband fitting for each cluster member, deriving the probability density function (PDF) of its primary mass (M_1_) and q in the Bayesian framework. 1154 main-sequence (MS) single stars or unresolved MS+MS binaries are identified as members of the Pleiades. By stacking their PDFs, we conducted a detailed analysis of binary properties of the cluster. We found the fb of this sample is 0.34+/-0.02. The q distribution exhibits a three-segment power-law profile: an initial increase, followed by a decrease, and then another increase. This distribution can be interpreted as a fiducial power-law profile with an exponent of -1.0 that is determined in the range of 0.3<q<0.8, but with a deficiency of binaries at lower q and an excess at higher q. The variations of fb and q with M_1_ reveal a complex binary distribution within the Pleiades, which might be attributed to a combination of primordial binary formation mechanisms, dynamical interactions, and the observational limit of photometric binaries imposed by q_lim_(M_1_).2025AJ....169..116Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/169/116CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)VII/233 : 2MASS All-Sky Extended Src Cat. (XSC) (IPAC/UMass, 2003-2006)J/A+A/323/139 : K magnitude of Pleiades low-mass binaries (Bouvier+ 1997)J/MNRAS/342/1241 : Low-mass stars in M45 and M44 (Pinfield+, 2003)J/MNRAS/380/712 : ZYJHK photometry in Pleiades (Lodieu+, 2007)J/A+A/615/A24 : Passband reconstruction from photometry (Weiler+, 2018)J/A+A/622/A110 : Spectroscopic membership for NGC 3532 (Fritzewski+, 2019)J/A+A/628/A66 : alpha Persei, Pleiades and Praesepe clusters (Lodieu+, 2019)J/MNRAS/489/3093 : Gaia DR2 parallax of globular clusters (Shao+, 2019)J/A+A/633/A99 : Gaia DR2 open clusters in the MW. II (Cantat-Gaudin+, 2020)J/ApJ/901/91 : Sp. obs. of rapidly rot. stars in the Pleiades (Torres, 2020)J/A+A/649/A3 : Gaia Early Data Release 3 phot. passbands (Riello+, 2021)J/AJ/161/160 : BINOCS: NEWFIRM & IRAC IR phot. of clusters (Thompson+, 2021)J/ApJ/921/117 : 43yr spectrosc. monitoring of Pleiades region (Torres+, 2021)J/A+A/668/A4 : LAMOST open clusters (Fu+, 2022)J/A+A/672/A29 : 78 Galactic Open cluster structural param. (Cordoni+, 2023)J/A+A/675/A89 : Multiplicity fractions in Gaia open clusters (Donada+, 2023)J/A+A/673/A114 : Improving the open cluster census. II. (Hunt+, 2023)J/AJ/165/45 : (H-W2)-W1 vs W2-(BP-K) for 4 open clust. memb. (Malofeeva+, 2023)J/AJ/168/156 : Pleiades members from Gaia DR3 (Chulkov+, 2024)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/169/116https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/169/116http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/169/116https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/169/116https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/169/116http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/169/116GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/169/116/table1 (Observational data and kinematic membership probabilities of stars in the region of the Pleiades)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/169/116/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/169/116/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/169/116/table1?GETtext/xml+votable180.050000true58.015120815.35998670.005555555555555556Cone search capability for table J/AJ/169/116/table4 (Results of multiband fitting for stars with P_k_>=0.5)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/169/116/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/169/116/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/169/116/table4?GETtext/xml+votable180.050000true57.293476116.64722690.0055555555555555563/7 4/19 22-23 25 27 52-53 72 74 5/71 82-83 86-87 97 99 105 107 196-197 199 264 266-267 292 294 300 384-385 6/283 295 301-303 323 326-327 338-339 773 792-793 821 864-865 868-869 871 880-881 884-885 1032 1034-1035 1060 1062-1063 1080 1082-1083 1208 1210 1544-1546 15488.650015785639275e-20 4.621782916333392e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/169/116?format=asciiOpticalInfrareddefaultJ/AJ/169/116/table1Observational data and kinematic membership probabilities of stars in the region of the PleiadesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR3Gaia DR3 (I/355) identifiermeta.id;meta.mainprimaryRAdeg[46/67] Gaia DR3 right ascension (ICRS at Epoch=J2016.0)degpos.eq.raDEdeg[15/33] Gaia DR3 declination (ICRS at Epoch=J2016.0)degpos.eq.decpmRA[-160/612] Gaia DR3 proper motion along RAmas/yrpos.pm;pos.eq.rafloate_pmRA[0.01/1.3] Uncertainty in pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDE[-529/84] Gaia DR3 proper motion along DEmas/yrpos.pm;pos.eq.decfloate_pmDE[0.01/0.9] Uncertainty in pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatplx[6.14/8.6] Gaia DR3 parallaxmaspos.parallax.trigfloate_plx[0.01/1.3] Uncertainty in plxmasstat.error;pos.parallaxfloatRUWE[0.6/54.5] Gaia DR3 renormalized unit weight errorstat.errorfloatPk[0/1] Kinematic membership probabilitystat.probabilityfloatTab4Link to multiband fitting results for stars with Pk>0.5 (Table 4)meta.numberintnullablem-M[5.3/6.1] Distance modulusmagphot.mag.distModfloatBPmag[3.5/21.7]? Gaia DR3 blue passband apparent magnitudemagphot.mag;em.opt.Bfloatnullablee_BPmag[3e-3/0.8]? Uncertainty in BPmagmagstat.error;phot.mag;em.opt.BfloatnullableGmag[3.6/19] Gaia DR3 G band apparent magnitudemagphot.mag;em.optfloate_Gmag[3e-3/0.04] Uncertainty in Gmagmagstat.error;phot.mag;em.optfloatRPmag[3.6/19]? Gaia DR3 red passband apparent magnitudemagphot.mag;em.opt.Rfloatnullablee_RPmag[4e-3/0.81]? Uncertainty in RPmagmagstat.error;phot.mag;em.opt.RfloatnullableJmag[3.1/16.9]? 2MASS (II/246) J band apparent magnitudemagphot.mag;em.IR.Jfloatnullablee_Jmag[0.02/0.3]? Uncertainty in Jmagmagstat.error;phot.mag;em.IR.JfloatnullableHmag[2.5/16.5]? 2MASS (II/246) H band apparent magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag[0.01/10]? Uncertainty in Hmagmagstat.error;phot.mag;em.IR.HfloatnullableKsmag[2.2/16.2]? 2MASS (II/246) Ks band apparent magnitudemagphot.mag;em.IR.Kfloatnullablee_Ksmag[0.01/10]? Uncertainty in Ksmagmagstat.error;phot.mag;em.IR.Kfloatnullable2MASSLink to 2MASS (II/246) catalogmeta.ref.urlintnullable_RAJ2000 positions from Gaia DR3 (I/355) (right ascension part)degpos.eq.ra;meta.main_DEJ2000 positions from Gaia DR3 (I/355) (declination part)degpos.eq.dec;meta.mainJ/AJ/169/116/table4Results of multiband fitting for stars with P_k_>=0.5GaiaDR3Gaia DR3 (I/355) identifiermeta.id;meta.mainSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintM1[0.09/4.9]? Best-fit primary mass valuesolMassphys.mass;meta.modelledfloatnullableq[0/1]? Best-fit mass ratio value; M2/M1phys.mass;arith.ratio;meta.modelledfloatnullableM1_16[0.09/4.81]? The 16% quantile for the primary masssolMassstat.error;phys.massfloatnullableM1_50[0.09/4.9]? The 50% quantile for the primary masssolMassstat.error;phys.massfloatnullableM1_84[0.09/4.9]? The 84% quantile for the primary masssolMassstat.error;phys.massfloatnullableq16[0.01/0.98]? The 16% quantile for the mass ratiostat.error;phys.mass;arith.ratiofloatnullableq50[0.03/0.99]? The 50% quantile for the mass ratiostat.error;phys.mass;arith.ratiofloatnullableq84[0.06/1]? The 84% quantile for the mass ratiostat.error;phys.mass;arith.ratiofloatnullablePb[0/1]? Probability of a star being a binary (1)stat.probabilityfloatnullable_RAPositions from Simbad (right ascension part)degpos.eq.ra;meta.main_DEPositions from Simbad (declination part)degpos.eq.dec;meta.mainFlagExclusion flag (s) (2)meta.code.errorcharJ/AJ/169/116/table3The fiducial photometric model and its correction of the Gaia and 2MASS bands for the PleiadesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMs[0.09/4.9] Initial stellar masssolMassphys.massfloatBPmag[-2/16.7] Gaia DR3 (I/355) blue passband magnitude (1)magphot.mag;em.opt.BfloatGmag[-2/13.9] Gaia DR3 (I/355) G band magnitude (1)magphot.mag;em.optfloatRPmag[-2/12.4] Gaia DR3 (I/355) red passband magnitude (1)magphot.mag;em.opt.RfloatJmag[-1.9/9.7] 2MASS (II/246) J band magnitude (1)magphot.mag;em.IR.JfloatHmag[-1.8/9.1] 2MASS (II/246) H band magnitude (1)magphot.mag;em.IR.HfloatKsmag[-1.8/8.8] 2MASS (II/246) Ks band magnitude (1)magphot.mag;em.IR.KfloatDelBP[-0.7/0.05] Gaia DR3 blue passband correctionmagphot.mag;em.opt.B;arith.difffloatDelG[-0.04/0.03] Gaia DR3 G passband correctionmagphot.mag;em.opt;arith.difffloatDelRP[-0.04/0.04] Gaia DR3 red passband correctionmagphot.mag;em.opt.R;arith.difffloatDelJ[-0.12/0.51] 2MASS J band correctionmagphot.mag;em.IR.J;arith.difffloatDelH[-0.11/0.51] 2MASS H band correctionmagphot.mag;em.IR.H;arith.difffloatDelKs[-0.11/0.44] 2MASS Ks band correctionmagphot.mag;em.IR.K;arith.difffloat