J/A+A/623/A22ivo://CDS.VizieR/J/A+A/623/A22doi:10.26093/cds/vizier.36230022CDSStraizys V.Boyle R. P.Milasius K.Cernis K.Macijauskas M.,Munari U.Janusz R.Zdanavicius J.Zdanavicius K.Maskoliunas M.,Raudeliunas S.Kazlauskas A.2019-02-27T12:52:25Z2019-02-26T07:57:28ZCDS support team

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

cds-question@unistra.fropen-star-clustersvilnius-photometryThe open cluster IC 4996 in Cygnus and its vicinity are investigated applying two-dimensional photometric classification of stars measured in the Vilnius seven-color photometric system. Cluster members are identified by applying distances based on the Gaia DR2 parallaxes and the point vector diagram of the Gaia DR2 proper motions. For some B-type stars, spectroscopic MK types are also obtained from the Asiago spectra and collected from the literature. New parameters of the cluster are derived. Th interstellar extinction A(v) covers a wide range of values, from 1.3 to 2.4mag, the mean value in the central part of the cluster is 1.8mag. The cluster distance is 1915+/-110pc, and its age is within 8-10Myr. The cluster exhibits a long sequence from early B to G stars, where stars cooler than B8 are in the pre-main-sequence stage. The plot of the extinction versus distance shows a steep rise of A(v) up to 1.6mag at 700-800pc, which is probably related to dust clouds at the edge of the Great Cygnus Rift. The next extinction rise by an additional 0.8 mag at d>=1.7kpc is probably related to the associations Cyg OB1 and Cyg OB3. The cluster IC 4996 does not belong to the Cyg OB1 association, which is located closer to the Sun, at 1682+/-116pc. It seems likely that the cluster and the surrounding O-B stars have a common origin with the nearby association Cyg OB3 since the Gaia data show that these stellar groups are located at a similar distance.2019A&A...623A..22Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/623/A22CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/623/A22https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/623/A22http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/623/A22https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/623/A22https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/623/A22http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/623/A22GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/623/A22/table1 (Catalogue of stars observed in the Vilnius seven-color system at the Maidanak Observatory)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/623/A22/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/623/A22/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/623/A22/table1?GETtext/xml+votable180.050000true303.781083337.640750.005555555555555556Cone search capability for table J/A+A/623/A22/table2 (Catalogue of stars observed in the Vilnius seven-color system at the Mount Graham observatory)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/623/A22/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/623/A22/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/623/A22/table2?GETtext/xml+votable180.050000true303.995041737.73288890.005555555555555556Cone search capability for table J/A+A/623/A22/table4 (List of probable members of the cluster IC 4996)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/623/A22/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/623/A22/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/623/A22/table4?GETtext/xml+votable180.050000true304.00937.69169440.005555555555555556Cone search capability for table J/A+A/623/A22/table5 (List of members of the association Cyg OB1)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/623/A22/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/623/A22/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/623/A22/table5?GETtext/xml+votable180.050000true302.937458337.54997220.0055555555555555565/3660-3661 6/14617 14619 14622-14623 14652-146533.561607812030676e-19 3.741500294832266e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/623/A22?format=asciiOpticaldefaultJ/A+A/623/A22/table1Catalogue of stars observed in the Vilnius seven-color system at the Maidanak ObservatoryVmagV magnitude (Vilnius system)magphot.mag;em.opt.VfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqSequential number (AK1-AK76)meta.recordcharn_Seq[*] indicates the star common with table2.datmeta.notecharRAJ2000Right ascension (J2000.0)pos.eq.ra;meta.mainDEJ2000Declination (J2000.0)pos.eq.dec;meta.mainU-VU-V colour index (Vilnius system)magphot.color;em.opt.U;em.opt.VfloatP-VP-V colour index (Vilnius system)magphot.color;em.opt.V;em.opt.UfloatX-VX-V colour index (Vilnius system)magphot.color;em.opt.V;em.opt.BfloatY-VY-V colour index (Vilnius system)magphot.color;em.opt.B;em.opt.VfloatZ-VZ-V colour index (Vilnius system)magphot.color;em.opt.V;em.opt.VfloatV-SV-S colour index (Vilnius system)magphot.color;em.opt.V;em.opt.RfloatSpTypePhotometric spectral type (1)src.spTypecharBin[**] ** for visual binary or multiple starmeta.codecharJ/A+A/623/A22/table2Catalogue of stars observed in the Vilnius seven-color system at the Mount Graham observatoryP-V? P-V colour index (Vilnius system)magphot.color;em.opt.V;em.opt.UfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/1337] Sequential numbermeta.recordintRAJ2000Right ascension (J2000.0)pos.eq.ra;meta.mainDEJ2000Declination (J2000.0)pos.eq.dec;meta.mainVmagV magnitude (Vilnius system)magphot.mag;em.opt.VfloatU-V? U-V colour index (Vilnius system)magphot.color;em.opt.U;em.opt.VfloatnullableX-VX-V colour index (Vilnius system)magphot.color;em.opt.V;em.opt.BfloatY-VY-V colour index (Vilnius system)magphot.color;em.opt.B;em.opt.VfloatZ-VZ-V colour index (Vilnius system)magphot.color;em.opt.V;em.opt.VfloatV-S? V-S colour index (Vilnius system)magphot.color;em.opt.V;em.opt.RfloatnullableSpTypePhotometric spectral type (1)src.spTypecharBin[**] ** for visual binary or multiple starmeta.codecharPmemb[PM ] PM for probable member with data in table4meta.codecharJ/A+A/623/A22/table4List of probable members of the cluster IC 4996DEJ2000Declination (J2000.0)pos.eq.dec;meta.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar number from table2, table1, HD or BDmeta.id;meta.maincharBin[*] * for visual binary or multiple starmeta.codecharRAJ2000Right ascension (J2000.0)pos.eq.ra;meta.mainVmagV magnitude (Vilnius system)magphot.mag;em.opt.VfloatSpTypeMK spectral type (1)src.spTypecharAv? Interstellar extinction in the V bandmagphys.absorption;em.opt.Vfloatnullable(Y-V)0? Intrinsic (Y-V) color index (Vilnius system)magphot.color;em.opt.B;em.opt.VfloatnullableVmag0? Vmag-Av (Vilnius system)magphot.mag;em.opt.VfloatnullableBC? Bolometric correctionmagphot.mag.bcfloatnullablelogTeff? Effective temperature of the star (log)log(K)phys.temperature.effectivefloatnullablelogL? Luminosity of the star (log)log(solLum)phys.luminosityfloatnullablepmRAProper motion in right ascension direction (pmRA*cosDE) (1)mas/yrpos.pm;pos.eq.rafloate_pmRAStandard error of proper motion in right ascension direction (1)mas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion in declination direction (1)mas/yrpos.pm;pos.eq.decfloate_pmDEStandard error of proper motion in declination direction (1)mas/yrstat.error;pos.pm;pos.eq.decfloatDistDistance of the star (2)pcpos.distance;pos.heliocentricintProb? Probability of membershipstat.probabilityfloatnullableJ/A+A/623/A22/table5List of members of the association Cyg OB1recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar IDmeta.id;meta.maincharRAJ2000Right ascension (J2000.0)pos.eq.ra;meta.mainDEJ2000Declination (J2000.0)pos.eq.dec;meta.mainVmagV magnitude (1)magphot.mag;em.opt.VfloatSptypeMK spectral type (1)src.spTypecharpmRAProper motion in right ascension direction (pmRA*cosDE) (2)mas/yrpos.pm;pos.eq.rafloate_pmRAStandard error of proper motion in right ascension direction (2)mas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion in declination direction (2)mas/yrpos.pm;pos.eq.decfloate_pmDEStandard error of proper motion in declination direction (2)mas/yrstat.error;pos.pm;pos.eq.decfloatDistDistance of the star (3)pcpos.distance;pos.heliocentricfloatSimbadSimbad column added by the CDSmeta.ref.urlchar