J/A+A/706/A251ivo://CDS.VizieR/J/A+A/706/A251CDSMinniti D.Lopez M.Alonso-Garcia J.Cortes-Contreras M.Cruz P.,Fernandez-Trincado J.G.Saito R.K.Fermiano V.Borissova J.Caceres C.,Gomez M.Gramajo L.V.Guo Z.Ivanov V.D.Kurtev R.Lucas P.W.,Majaess D.Obasi C.Palma T.Pullen J.B.Ramirez K.P.Sanders J.,Smith L.C.Solano E.2026-03-02T06:25:50Z2026-02-17T11:18:32ZCDS support team

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

cds-question@unistra.frmilky-way-galaxyopen-star-clustersm-starsproper-motionsinfrared-photometrychemical-abundancesWhile large samples of nearby M dwarfs are becoming available, it is usually difficult to estimate some intrinsic physical parameters for isolated field M dwarfs, especially their ages, radii, and masses. These parameters can be estimated through a comparison with model stellar isochrones and/or by studying eclipsing binary systems. Our goal is to gather and analyze a large sample of variable M dwarfs that are members of nearby young open clusters and have known reddenings, distances, ages, and metallicities. This distilled sample would be useful for the comparison with theoretical models and also for the identification of eclipsing binaries with substellar companions (brown dwarfs or giant planets) for future follow-up. We selected two dozen benchmark young and nearby open clusters (mostly with 40<age<132Myr and 400<D<700pc, respectively). We then combined the optical data from Gaia Data Release 3 (DR3) with near-IR JHKs -band photometry from the VISTA Variables in the Via Lactea eXtended survey (VVVX) for these target clusters using the proper motions in order to select members within the cluster radii. Gaia and VVVX both provide a wide areal coverage that is ideally suited for mapping these nearby clusters, which are extended on the sky. We then produced optical and near-IR color-magnitude and color-color diagrams and applied appropriate color cuts to choose the M-type dwarfs at the end of the main sequence. The reddening and extinction for all clusters were estimated using the J-Ks color distributions of the cluster M dwarfs. We also compared them with the PARSEC theoretical isochrones adjusted to the respective cluster metallicities, ages, extinctions, and distances. Finally, we selected variable M stars according to Gaia DR3 (using phot_variable_flag=VARIABLE) and present a catalog of 318 variable M-dwarf star members of two dozen young nearby Galactic open clusters. The cross-validation with the Gaia DR3 parallaxes supports the cluster membership for all these sources. We also present a few examples to validate the sample of variable cluster M dwarfs. This well-characterized catalog of M-dwarf members of benchmark open clusters not only constitutes a prime sample to search for transiting substellar companions, but also offers a training dataset for machine-learning applications aimed at selecting future similar targets.2026A&A...706A.251Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/706/A251CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/706/A251https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/706/A251http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/706/A251https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/706/A251https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/706/A251http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/706/A251GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/706/A251/clusters (*Physical parameters of the open clusters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/706/A251/clusters?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/706/A251/clusters?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/706/A251/clusters?GETtext/xml+votable180.050000true131.975004-37.9833410.005555555555555556Cone search capability for table J/A+A/706/A251/variable (Astrometric and photometric data for variable M-dwarf stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/706/A251/variable?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/706/A251/variable?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/706/A251/variable?GETtext/xml+votable180.050000true160.9271-61.10030.0055555555555555565/9466 9974 6/21523 21528-21529 21531 28806-28807 28812 29081 29083-29084 29086 37332-37333 37335 37723 37745 37892 37933 37944 38018-38019 38027 38049-38051 38054 38057 39232-39233 39235-39236 39241 39243-39244 39249-39251 39254 39256-39257 39375 39397 39751 39761-39763 39769-39770 39779 39782 39785 39879 39885-39886 39890 39968 39970 41843 41846 42147-42148 42150 42407 42418-42419 42422 42424-42425 42428 424647.952274030004205e-20 1.7798557115773645e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/706/A251?format=asciiInfrareddefaultJ/A+A/706/A251/clusters*Physical parameters of the open clustersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameOpen cluster namemeta.id;meta.maincharGLONGalactic longitude of the cluster centerdegpos.galactic.lonGLATGalactic latitude of the cluster centerdegpos.galactic.latpmRAMean proper motion in right ascensionmas/yrpos.pm;pos.eq.rafloatpmDEMean proper motion in declinationmas/yrpos.pm;pos.eq.decfloatDistHeliocentric distance to the clusterpcpos.distanceintplxMean parallax of the clustermas/yrpos.parallax.trigfloatAgeCluster ageMyrtime.ageintSizeAngular radius of the clusterarcminphys.angSizeint[Fe/H]? Mean cluster metallicityphys.abund.Z;stat.meanfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.raindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.decindexedJ/A+A/706/A251/variableAstrometric and photometric data for variable M-dwarf starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR3Variable star Gaia IDmeta.id;meta.mainRAJ2000Right ascension (J2000.0)degpos.eq.ra;meta.mainDEJ2000Declination (J2000.0)degpos.eq.dec;meta.mainplxParallaxmaspos.parallax.trigfloatpmRAProper motion in RAmas/yrpos.pm;pos.eq.rafloatpmDEProper motion in DECmas/yrpos.pm;pos.eq.decfloatGmagG magnitudemagphot.mag;em.optfloatBP-RPGaia BP-RP colormagphot.color;em.opt.B;em.opt.RfloatJmagJ magnitudemagphot.mag;em.IR.Jfloate_Jmag? Error on J magnitudemagstat.error;phot.magfloatnullableHmag? H magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag? Error on H magnitudemagstat.error;phot.magfloatnullableKsmagKs magnitudemagphot.mag;em.IR.Kfloate_Ksmag? Error in Ks magnitudemagstat.error;phot.magfloatnullable