J/A+A/509/A11ivo://CDS.VizieR/J/A+A/509/A11doi:10.26093/cds/vizier.35090011CDSMartayan C.Baade D.Fabregat J.2026-01-20T12:10:42Z2010-03-27T18:32:13ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsemission-line-starsinfrared-photometryvisible-astronomybroad-band-photometrySlitless CCD spectra were obtained covering the bulk (about 3 square degrees) of the Small Magellanic Cloud. For H{alpha} line-emission twice as strong as the ambient continuum, the survey is complete to spectral type B2/B3 on the main sequence. About 8120 spectra of 4437 stars were searched for emission lines in 84 open clusters, and 370 emission-line stars were found, among them at least 231 close to the main sequence. For 176 of them, photometry is available from the OGLE database. For comparison with a higher-metallicity environment, the Galactic sample of the photometric H{alpha} survey by McSwain & Gies (2005, Cat. <J/ApJS/161/118>) was used. Among early spectral sub-types, Be stars are more frequent by a factor ~3-5 in the SMC than in the Galaxy. The distribution with spectral type is similar in both galaxies, i.e., not strongly dependent on metallicity. The fraction of Be stars does not seem to vary with local star density. The Be phenomenon mainly sets in towards the end of the main-sequence evolution (this trend may be more pronounced in the SMC); but some Be stars already form with Be-star characteristics. In small subsamples (such as single clusters), even if they appear identical, the fraction of emission-line stars can deviate drastically from the mean. In all probability, the fractional critical angular rotation rate, OMC, is one of the main parameters governing the occurrence of the Be phenomenon. If the Be character is only acquired during the course of evolution, the key circumstance is the evolution of OMC, which is not only dependent on metallicity but differently so for different mass ranges. As a result, even if the Be phenomenon is driven basically by a single parameter (namely OMC), it can assume a complex multi-parametric appearance. The large cluster-to-cluster differences, which seem stronger than all other variations, serve as a caveat that this big picture may undergo significant second-order modulations (e.g., pulsations, initial angular momentum, etc).2010A&A...509A..11Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/509/A11CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/311/741 : SMC emission-line objects (Murphy+, 2000)J/A+AS/102/451 : Emission-line stars and PNe in the SMC (Meyssonnier+ 1993)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/509/A11https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/509/A11http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/509/A11https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/509/A11https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/509/A11http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/509/A11GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/509/A11/tablea (Emission-line stars in NGC 346 (parts 1 and 2))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/509/A11/tablea?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/509/A11/tablea?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/509/A11/tablea?GETtext/xml+votable180.050000true14.80118333-72.166236110.005555555555555556Cone search capability for table J/A+A/509/A11/tableb1 (*Data for individual observations of open clusters in the SMC)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/509/A11/tableb1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/509/A11/tableb1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/509/A11/tableb1?GETtext/xml+votable180.050000trueCone search capability for table J/A+A/509/A11/tableb2 (Details about the individual open clusters with different observations merged)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/509/A11/tableb2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/509/A11/tableb2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/509/A11/tableb2?GETtext/xml+votable180.050000true9.3879167-73.61183330.005555555555555556Cone search capability for table J/A+A/509/A11/tablec (SMC cluster stars cross-correlation of WFI with OGLE (Udalski et al., 1998, Cat. J/AcA/48/147), with corrected photometry and classification (tables C1 to C6 of paper))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/509/A11/tablec?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/509/A11/tablec?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/509/A11/tablec?GETtext/xml+votable180.050000true10.15355417-73.395038060.005555555555555556Cone search capability for table J/A+A/509/A11/tablec9 (Emission-line star from WFI without identification in SC catalogues from OGLE (Udalski et al. 1998, Cat. <J/AcA/48/147>))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/509/A11/tablec9?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/509/A11/tablec9?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/509/A11/tablec9?GETtext/xml+votable180.050000true10.35014167-72.898465830.0055555555555555566/33294-33295 33306 33316-33317 333281.1166583743361574e-19 4.920466254354166e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/509/A11?format=asciiOpticalInfrareddefaultJ/A+A/509/A11/tableaEmission-line stars in NGC 346 (parts 1 and 2)HclassH08 (Hennekemper et al., 2008ApJ...672..914H) classsrc.spTypecharSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/55] WFI[S11] NGC 346- numbermeta.id;meta.mainintRAJ2000WFI right ascension (J2000)pos.eq.ra;meta.mainDEJ2000WFI declination (J2000)pos.eq.dec;meta.mainRA2? 2MASS right ascension (J2000)pos.eq.ranullableDE2? 2MASS declination (J2000)pos.eq.decnullableRAe? EIS right ascension (J2000)pos.eq.ranullableDEe? EIS declination (J2000)pos.eq.decnullableBmag? EIS B magnitudemagphot.mag;em.opt.Bfloatnullablen_Bmag[s] s when magnitude from Simbadmeta.notecharVmagEIS V magnitudemagphot.mag;em.opt.Vfloatn_Vmag[s] s when magnitude from Simbadmeta.notecharImag? Denis I magnitudemagphot.mag;em.opt.IfloatnullableJmag? 2MASS J magnitudemagphot.mag;em.IR.JfloatnullableHmag? 2MASS H magnitudemagphot.mag;em.IR.HfloatnullableKmag? 2MASS K magnitudemagphot.mag;em.IR.KfloatnullableEISEIS name (SMC5 NNNNNN)meta.idcharONameOther namemeta.idcharB-V? B-V colour indexmagphot.color;em.opt.B;em.opt.VfloatnullableE(B-V)Colour excessmagphot.color.excessfloat(B-V)0? Deredenned B-V colour indexmagphot.color;em.opt.B;em.opt.VfloatnullableV0magDeredenned V magnitudemagphot.mag.reddFree;em.opt.VfloatVMAGAbsolute V magnitudemagphys.magAbsfloatSpTWFI spectral typesrc.spTypecharn_SpT[*] *: not main-sequencemeta.notecharclassSimbad spectral classsrc.spTypecharVclassVFS (Hunter et al., 2008, Cat. <J/A+A/479/541>) classsrc.spTypecharWclassWB07 (Wisniewski et al., 2007, Cat. <J/ApJ/671/2040>) classsrc.spTypecharSclassSpitzer (Nota et al., 2006ApJ...640L..29N) classsrc.classcharJ/A+A/509/A11/tableb1*Data for individual observations of open clusters in the SMCrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterCluster name (SMCNNN)meta.id.parentcharWFImgWFI image numberobs.imageintrRadius (1)arcsecphys.angSizeintl_logtLimit flag on logtmeta.code.errorcharlogtAge (from Pietrzynski & Udalski, 1999AcA....49..157P)log(yr)time.agefloatl_Z[<= ] Limit flag on Zmeta.code.error;src.redshiftcharSimbadSimbad column added by the CDSmeta.ref.urlcharZArea of metallicity (from Cioni et al., 2006A&A...452..195C)phys.abund.ZfloatZ2? Area of metallicity (from Cioni et al., 2006A&A...452..195C)phys.abund.ZfloatnullableN*Total number of stars/spectra extractedmeta.numberintNemNumber of definite emission-line stars foundmeta.numberintNem?Number of candidate emission-line stars foundmeta.numberintNem+Total number of (definite+candidate) emission line starsmeta.numberintem/tProportion in % of emission-line stars to the whole sample by open cluster%statfloatO*OGLE Total number of stars/spectra extracted (2)meta.numberintOemOGLE Number of definite emission-line stars found (2)meta.numberintOem?OGLE Number of candidate emission-line stars found (2)meta.numberintCommComments (3)meta.notecharNOGLE/WFI Total number of stars/spectra extractedmeta.numberfloatELS? OGLE/WFI Number of definite emission-line stars foundmeta.numberfloatnullableJ/A+A/509/A11/tableb2Details about the individual open clusters with different observations mergedClusterCluster name (SMCNNN)meta.id.parentcharprimary_RAPosition of the cluster (right ascension part)degpos.eq.ra;meta.main_DEPosition of the cluster (declination part)degpos.eq.dec;meta.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintOn*OGLE number of normal starsmeta.numberintOemOGLE number of emission-line starsmeta.numberintOem?OGLE number of candidate emission-line starsmeta.numberintNemNumber of emission-line stars not from OGLEmeta.numberintELS/allRatio of emission-line to all stars%statfloatBe? Number of Be starsmeta.numberintnullableBe?? Number of candidate Be starsmeta.numberintnullableB? Number of B starsmeta.numberintnullableBe/B? Ratio of Be to all B stars%statfloatnullableBe+/B? Ratio of (Be + candidate Be) to all b stars%statfloatnullableOe? Number of Oe starsmeta.numberintnullableO? Number of O starsmeta.numberintnullableOe/O? Ratio of Oe to all O stars%statfloatnullableAe? Number of Ae starsmeta.numberintnullableA? Number of A starsmeta.numberintnullableAe/A? Ratio of Ae to all A stars%statfloatnullableOBAe? Number of emission-line stars (Oe, Be and Ae)meta.numberintnullableOBA? Number of all O, B and A starsphot.mag;em.opt.BintnullableOBAe/OBA? Ratio of OBA emissions stars to all OBA starsstatfloatnullableF-Me? Number of emission-line stars from main sequence but not OBA typemeta.numberintnullableJ/A+A/509/A11/tablecSMC cluster stars cross-correlation of WFI with OGLE (Udalski et al., 1998, Cat. J/AcA/48/147), with corrected photometry and classification (tables C1 to C6 of paper)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCode[1/4] Code for object type (G1)src.classintClusterCluster name (SMCNNN)meta.id.parentcharWFImgWFI image numberobs.imageintOGLEimgOGLE image numberobs.imagecharWFIWFI sequential numbermeta.recordintOGLEOGLE sequential numbermeta.idintRadDistance between OGLE and WFI positionsarcsecpos.angDistancefloatRAJ2000WFI right ascension (J2000)pos.eq.ra;meta.mainDEJ2000WFI declination (J2000)pos.eq.dec;meta.mainRA2OGLE right ascension (J2000)pos.eq.raDE2OGLE declination (J2000)pos.eq.decVmagV magnitudemagphot.mag;em.opt.VfloatSimbadSimbad column added by the CDSmeta.ref.urlcharBmag? B magnitudemagphot.mag;em.opt.BfloatnullableImagI magnitudemagphot.mag;em.opt.IfloatB-V? B-V colour indexmagphot.color;em.opt.B;em.opt.VfloatnullableV-IV-I colour indexmagphot.color;em.opt.V;em.opt.IfloatE(B-V)Colour excessmagphot.color.excessfloatlogtAgelog(yr)time.agefloatMultCode for multiple WFI observations (1)meta.numberint(B-V)0? Corrected B-V colour indexmagphot.color;em.opt.B;em.opt.VfloatnullableV0magCorrected V magnitudemagphot.mag.reddFree;em.opt.VfloatVMAGAbsolute V magnitudemagphys.magAbsfloat(V-I)0Corrected V-I colour indexmagphot.color;em.opt.V;em.opt.IfloatSpTSpectral typesrc.spTypecharSNameSimbad namemeta.idcharu_SName[?] ? indicates a poor degree of confidence on the identification in Simbadmeta.code.errorcharStypeSimbad object typesrc.classcharJ/A+A/509/A11/tablec9Emission-line star from WFI without identification in SC catalogues from OGLE (Udalski et al. 1998, Cat. <J/AcA/48/147>)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterCluster name (SMCNNN)meta.id.parentcharWFImgWFI image numberobs.imageintWFIWFI sequential numbermeta.recordintRAJ2000WFI right ascension (J2000)pos.eq.ra;meta.mainDEJ2000WFI declination (J2000)pos.eq.dec;meta.mainSimbadSimbad column added by the CDSmeta.ref.urlcharE(B-V)Colour excessmagphot.color.excessfloatlogtAgelog(yr)time.agefloatStatusStatus (ELS or ELS?)meta.codecharSNameSimbad namemeta.idcharu_SName[?] ? indicates a poor degree of confidence on the identification in Simbadmeta.code.errorcharStypeSimbad object typesrc.classchar