J/MNRAS/541/1866ivo://CDS.VizieR/J/MNRAS/541/1866doi:10.26093/cds/vizier/bg-gx-1taCDSChakraborty A.Jose J.Carciofi A.C.2026-10-07T13:03:09Z2025-12-31T10:27:33ZCDS support team

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

cds-question@unistra.fremission-line-starsbe-starsvariable-starsNGC 7419 is a young open cluster notable for hosting five red supergiants and a high abundance of Classical Be (CBe) stars. CBe stars are main-sequence non-supergiant B-type stars that exhibit or have exhibited Balmer-line emissions in their spectra. We perform a membership analysis using Gaia DR3 data and machine learning techniques like Gaussian mixture models and Random Forest and determine the cluster's mean distance to be 3.6^+1.0^_-0.6_kpc. We identify 499 Gaia-based members with a mass above ~1.2M_{sun}_, and estimate the cluster's age to be 21.1^+1.6^_-0.6_Myr. Using our revised Halpha excess-based analysis, we find 42 CBe stars containing many known CBe stars, bringing the total number of CBe stars in NGC 7419 to 49 and the fraction of CBe to (B + CBe) members to 12.7 per cent. We investigate the variability of the candidate members from Zwicky Transient Facility and NEOWISE data using standard deviation, median absolute deviation, and Stetson index (J), and their periodicity using the Generalized Lomb-Scargle periodogram variability. We find that 66 per cent of CBe stars are variable: 23 per cent show periodic signals, typical of pulsation/rotation, 41 per cent display variability characteristic of disc dynamics or binarity, and 14 per cent exhibit long-term changes, consistent with disc dissipation/formation. We also find that all pulsating CBe stars are early-type, while 50 per cent of stars with long-term variations are early-type, and the other 50 per cent are mid-type. Our results agree with previous findings in the literature and confirm that CBe stars display variability through multiple mechanisms across different time-scales.2025MNRAS.541.1866Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/541/1866CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/other/BASI/39.517 : Spectroscopy of classical Be stars (Mathew+, 2011)J/ApJS/208/9 : PMS stars intrinsic colors & temperatures (Pecaut+, 2013)J/A+A/552/A92 : uvby photometry in NGC 7419 (Marco+, 2013)J/ApJS/93/187 : UBV Photometry in NGC 7419 (Beauchamp+ 1994)J/MNRAS/391/1279 : Multiwavelength study of NGC 7419 (Joshi+, 2008)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/541/1866https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/541/1866http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/541/1866https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/541/1866https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/541/1866http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/541/1866GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/541/1866/table1 (NGC 7419 members (updated table, 07/10/2026))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/541/1866/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/541/1866/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/541/1866/table1?GETtext/xml+votable180.050000true343.1762160.838880.005555555555555556Cone search capability for table J/MNRAS/541/1866/table2 (Variability and periodicity of NGC 7419 members in ZTF r band data (updated table, 07/10/2026))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/541/1866/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/541/1866/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/541/1866/table2?GETtext/xml+votable180.050000true343.1764660.848320.005555555555555556Cone search capability for table J/MNRAS/541/1866/table3 (Variability and periodicity of NGC 7419 members in NEOWISE data (updated table, 07/10/2026))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/541/1866/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/541/1866/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/541/1866/table3?GETtext/xml+votable180.050000true343.1761760.838970.005555555555555556Cone search capability for table J/MNRAS/541/1866/table4 (NGC 7419 B-type members (updated table, 07/10/2026))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/541/1866/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/541/1866/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/541/1866/table4?GETtext/xml+votable180.050000true343.1764560.848310.0055555555555555566/143141.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/541/1866?format=asciidefaultJ/MNRAS/541/1866/table1NGC 7419 members (updated table, 07/10/2026)_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.raindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.decindexedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMoreindicates more data in tables 2, 3 and/or 4meta.ref.urlcharStarIDUnique identifier for each NGC 7419 membermeta.id;meta.mainintprimaryGaiaDR3Unique Gaia DR3 source identifiermeta.idRA_ICRSRight Ascension of the star (ICRS) at Ep=2016degpos.eq.ra;meta.mainDE_ICRSDeclination of the star (ICRS) at Ep=2016degpos.eq.dec;meta.mainPlxParallaxmaspos.parallaxfloatpmRAProper motion in Right Ascensionmas/yrpos.pm;pos.eq.rafloatpmDEProper motion in Declinationmas/yrpos.pm;pos.eq.decfloatGmagGaia G-band apparent magnitudemagphot.mag;em.optfloatBPmagGaia blue photometric band apparent magnitudemagphot.mag;em.opt.BfloatRPmagGaia red photometric band apparent magnitudemagphot.mag;em.opt.Rfloatpmemb? Probability that the star is a member of NGC 7419 (1)meta.id.parent;stat.probabilityfloatnullableJ/MNRAS/541/1866/table2Variability and periodicity of NGC 7419 members in ZTF r band data (updated table, 07/10/2026)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarIDUnique identifier for each NGC 7419 membermeta.id;meta.mainintOIdZTF object identifiermeta.idRAJ2000Right Ascension of the star (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of the star (J2000)degpos.eq.dec;meta.mainrmagApparent r-band magnitude of the starmagphot.mag;em.opt.RfloatStetsonIndexStetson variability index, a measure of variabilitymeta.code;src.var.indexfloatVar[0/1] Indicates if the star is variable or notmeta.codeintPer1? Period 1 of variability in r-banddsrc.vardoublenullablePer2? Period 2 of variability in r-banddsrc.varfloatnullableJ/MNRAS/541/1866/table3Variability and periodicity of NGC 7419 members in NEOWISE data (updated table, 07/10/2026)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarIDUnique identifier for each NGC 7419 membermeta.id;meta.mainintRAJ2000Right Ascension of the star (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of the star (J2000)degpos.eq.dec;meta.mainW1magApparent magnitude of the star in the W1 bandmagphot.mag;em.IR.3-4umfloatW2magApparent magnitude of the star in the W2 bandmagphot.mag;em.IR.4-8umfloatStetsonIndexStetson variability index, a measure of variabilitymeta.code;src.var.indexfloatVar[0/1] Indicates if the star is variable or notmeta.codeintPerW1? Period of variability in the W1 banddtime.perioddoublenullablePerW2-1? Period 1 of variability in the W2 banddsrc.vardoublenullablePerW2-2? Period 2 of variability in the W2 banddsrc.varfloatnullableJ/MNRAS/541/1866/table4NGC 7419 B-type members (updated table, 07/10/2026)SpTypeSpectral type of the sourcesrc.spTypecharn_SpTypeNote on SpType (2)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarID? Unique identifier for each NGC 7419 member (1)meta.id;meta.mainintnullableRA_ICRSRight Ascension of the star (ICRS) at Ep=2016degpos.eq.ra;meta.mainDE_ICRSDeclination of the star (ICRS) at Ep=2016degpos.eq.dec;meta.mainRadius? Stellar radius estimated from modified table of Pecaut and Mamajek (2013ApJS..208....9P, Cat. J/ApJS/208/9)solRadphys.angSize;srcfloatnullableMass? Stellar mass estimated from modified table of Pecaut and Mamajek (2013ApJS..208....9P, Cat. J/ApJS/208/9)solMassphys.massfloatnullableVbreakup? Breakup or critical velocity estimated using our estimated mass and radiuskm/sphys.velocfloatnullableVarZTF[0/1]? Indicates whether the star is variable or notmeta.codeintnullableVarNEOWISE[0/1]? Indicates whether the star is variable or notmeta.codeintnullablePerZTF1? Period 1 of variability in ZTF r-banddsrc.vardoublenullablePerZTF2? Period 2 of variability in ZTF r-banddsrc.varfloatnullablePerW1? Period of variability in NEOWISE W1 banddtime.perioddoublenullablePerW2-1? Period 1 of variability in NEOWISE W2 banddsrc.vardoublenullablePerW2-2? Period 2 of variability in NEOWISE W2 banddsrc.varfloatnullableCBe[0/1]? Indicates whether the star is a CBe star or notmeta.codeintnullable