J/A+A/376/144ivo://CDS.VizieR/J/A+A/376/144doi:10.26093/cds/vizier.33760144CDSPigulski A.Kopacki G.Kolaczkowski Z.2002-01-28T10:41:05Z2002-01-28T11:40:41ZCDS support team

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

cds-question@unistra.fropen-star-clustersbe-starsinfrared-photometryvisible-astronomybroad-band-photometrykron-cousins-photometryh-alpha-photometryWe present new BV(RI)_C_H{alpha} photometry of the young open cluster NGC 663. The H{alpha} photometry is complete down to magnitude R_C_=15.4, corresponding to spectral type A5 for the cluster members. This allows detection of mild and strong H{alpha} emission in all B-type stars in the cluster. In addition to the 22 Be stars known in the observed field of NGC 663, we discovered four new faint stars of this type. We find that Be stars in NGC 663 cover the whole range of the B spectral type. They are, however, most populous among stars with spectral types falling in the range between B0 and B3, where their fraction amounts to 31+/-8%. Among B-type stars later than B3, Be stars are much less abundant: only 7 out of 101 observed stars, that is, 7+/-3%, were detected. About 70% of the observed Be stars in NGC 663 show detectable variations of light. In the time interval covered by our observations, the ranges of the largest variations reach 0.4mag in the I_C_ band. By means of the isochrone fitting, we derived the cluster distance of 2.1kpc, age of 20-25Myr, and the mean colour excess E(R-I)_C_=0.54mag, with a ~0.1mag scatter due to differential reddening.2001A&A...376..144Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/376/144CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/376/144https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/376/144http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/376/144https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/376/144https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/376/144http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/376/144GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/376/144/table2 (BV(RI)c and H{alpha} photometry, coordinates and cross-identifications for observed stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/376/144/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/376/144/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/376/144/table2?GETtext/xml+votable180.050000true26.212708361.14041670.0055555555555555566/3632https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/376/144?format=asciiOpticalInfrareddefaultJ/A+A/376/144/table2BV(RI)c and H{alpha} photometry, coordinates and cross-identifications for observed starsBmag? B magnitudemagphot.mag;em.opt.Bfloatnullablealpha? {alpha} index (2)magphot.color;em.line.HalphafloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintXposX coordinate of a star in Fig.2, see Note (1)pixpos.cartesian.x;instr.detfloatYposY coordinate of a star in Fig.2pixpos.cartesian.y;instr.detdoubleRAJ2000Right Ascension (epoch J2000.0)pos.eq.ra;meta.mainDEJ2000Declination (epoch J2000.0)pos.eq.dec;meta.maino_Bmag? Number of B-filer measurementsmeta.numberintnullableo_Vmag? Number of V-filer measurementsmeta.numberintnullableo_Rcmag? Number of Rc-filer measurementsmeta.numberintnullableo_Icmag? Number of Ic-filer measurementsmeta.numberintnullableVmag? V magnitudemagphot.mag;em.opt.VfloatnullableRcmag? Cousins R magnitudemagphot.mag;em.opt.RfloatnullableIcmag? Cousins I magnitudemagphot.mag;em.opt.Ifloatnullablee_Bmag? Error of B magnitudemagstat.errorfloatnullablee_Vmag? Error of V magnitudemagstat.errorfloatnullablee_Rcmag? Error of Rc magnitudemagstat.errorfloatnullablee_Icmag? Error of Ic magnitudemagstat.errorfloatnullableo_alphanNumber of Halpha narrow filter measurements (2)meta.numberinto_alphawNumber of Halpha wide filter measurements (2)meta.numberinte_alpha? Error of {alpha} indexmagstat.errorfloatnullablePumStar number from Pummerer (1915, Publ. Sternw. Wien Ottakring 6 part VII, CL* NGC 663 PUM II-NNN)meta.idcharGus? Star number from Gushee (1919AJ.....32..117G, CL* NGC 663 G NNN)meta.idcharu_Gus[:] Uncertainty flag on Gus numbermeta.code.errorcharWal? Star number from Wallenquist (1929MeUpp..42.....W, NGC 663 NNN)meta.idcharprimaryu_Wal[:] Uncertainty flag on Wal numbermeta.code.errorcharn_Wal[*] *: object in table3.datmeta.notecharZug? Star number from Zug (1933LicOB..16..119Z, Cl* NGC 663 ZUG NN)meta.idintnullableBGStar number from Becker & Guenther (1947AN....275..145B, Cl* NGC 663 BG NNN)meta.idcharHH? Star number from Hopmann & Haidrich (1959MiWie..10..129H, Cl* NGC 663 HH NNN)meta.idintnullableHE? Star number from Hoag et al. (1961PUSNO..17..343H, Cl* NGC 663 HOAG NNW), photoelectric sequencemeta.idintnullableHP? Star number from Hoag et al. (1961PUSNO..17..343H, Cl* NGC 663 HOAG 1NN), photographic sequencemeta.idintnullableu_HP[:] Uncertainty flag on HP numbermeta.code.errorcharMH? Star number from McCuskey & Houk (1964AJ.....69..412M, Cl* NGC 663 MH NNN)meta.idintnullableu_MH[:] Uncertainty flag on MH numbermeta.code.errorcharLat? Star number from Latypov (1973TITas..39...12L, Cl* NGC 663 L NNNN)meta.idintnullableMV? Star number from Moffat & Vogt (1974VeBoc...2....1M, Cl* NGC 663 MV NNNNN)meta.idintnullableBR? Star number from van den Bergh & de Roux (1978AJ.....83.1075V, Cl* NGC 663 VD 3-NNN)meta.idintnullableTapStar number from Tapia et al. (1991MNRAS.253..649T, Cl* NGC 663 HOAG NNW)meta.idcharJ/A+A/376/144/table3Epoch H{alpha} photometry of the observed Be starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSan? Star number according to Sanduleak (1979AJ.....84.1319S, 1990AJ....100.1239S, Cl* NGC 663 SAN NNN in Simbad)meta.idintnullableWalStar number according to Wallenquist (1929MeUpp..42.....W)meta.id;meta.maincharEpochHJD of the epoch of observationdtime.epochdoublealpha{alpha} indexmagphot.color;em.line.Halphafloate_alphaError of {alpha} indexmagstat.errorfloat