J/ApJ/831/116ivo://CDS.VizieR/J/ApJ/831/116doi:10.26093/cds/vizier.18310116CDSLim B.Sung H.Kim J.S.Bessell M.S.Hwang N.Park B.-G.2022-08-16T11:56:16Z2018-04-20T06:58:14ZCDS support team

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

cds-question@unistra.frThe timescale of cluster formation is an essential parameter in order to understand the formation process of star clusters. Pre-main sequence (PMS) stars in nearby young open clusters reveal a large spread in brightness. If the spread were considered to be a result of a real spread in age, the corresponding cluster formation timescale would be about 5-20Myr. Hence it could be interpreted that star formation in an open cluster is prolonged for up to a few tens of Myr. However, difficulties in reddening correction, observational errors, and systematic uncertainties introduced by imperfect evolutionary models for PMS stars can result in an artificial age spread. Alternatively, we can utilize Li abundance as a relative age indicator of PMS star to determine the cluster formation timescale. The optical spectra of 134 PMS stars in NGC 2264 have been obtained with MMT/Hectochelle. The equivalent widths have been measured for 86 PMS stars with a detectable Li line (3500<{T}_eff[K]_<=6500).2016ApJ...831..116Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/831/116CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIII/274 : Galactic O-Star Spectroscopic Survey (Sota+, 2014)J/AJ/106/1059 : Lithium in the Pleiades (Soderblom+, 1993)J/AJ/105/2299 : Li abundance of solar-type stars. II. (Soderblom+, 1993)J/AJ/114/2644 : UBVRIHa photometry of NGC2264 (Sung+, 1997)J/A+A/333/231 : O-M stars model atmospheres (Bessell+ 1998)J/A+A/345/521 : BVRI photometry of NGC 2264 (Flaccomio+, 1999)J/ApJ/581/1194 : Taurus-Auriga PMS stars ages and Teff (Palla+, 2002)J/AJ/126/1916 : JHK photometry of young clusters near the SunJ/AJ/128/1684 : NGC 2264: VRIH{alpha} photometry (Sung+, 2004)J/AJ/129/829 : H{alpha} emission stars in NGC 2264 (Dahm+, 2005)J/ApJ/648/1090 : Radial velocities of NGC 2264 stars (Furesz+, 2006)J/AJ/134/999 : X-ray observations of NGC 2264 (Dahm+, 2007)J/AJ/135/441 : VRIH{alpha} photometry in NGC 2264 (Sung+, 2008)J/AJ/138/1116 : A Spitzer view of NGC 2264 (Sung+, 2009)J/AJ/145/46 : UBVIc photometry in Westerlund 1 (Lim+, 2013)J/AJ/145/37 : UBVI and H{alpha} CCD photometry of NGC 6231 (Sung+, 2013)J/MNRAS/438/1451 : UBVIH{alpha} photometry of IC 1848 (Lim+, 2014)J/MNRAS/443/454 : UBVIH{alpha} photometry in NGC 1893 (Lim+, 2014)J/ApJ/813/42 : O and B type stars in W3: first results (Kiminki+, 2015)J/AJ/149/127 : The SOS project. IV. NGC 1624 and NGC 1931 (Lim+, 2015)J/A+A/575/A57 : LQ Hya activity and Li variations (Flores Soriano+, 2015)J/AJ/149/119 : Radial velocities of stars in NGC 2264 (Tobin+, 2015)J/A+A/590/A78 : NGC2264 weak-line T Tauri lithium abundancesJ/A+A/586/A52 : NGC 2264, NGC 2547 and NGC 2516 stellar radiihttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/831/116https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/831/116http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/831/116https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/831/116https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/831/116http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/831/116GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/831/116/table2 (Photometric and spectroscopic data of 86 pre-main sequence stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/831/116/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/831/116/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/831/116/table2?GETtext/xml+votable180.050000true99.89341679.91422220.0055555555555555566/23636-23637 23639 238103.352923723967259e-19 3.9105737390043815e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/831/116?format=asciidefaultJ/ApJ/831/116/table2Photometric and spectroscopic data of 86 pre-main sequence starsVc-Ic[0.626/2.261] Cousins V-I color index (1)magphot.color;em.opt.V;em.opt.IfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID? Source IDmeta.id;meta.maincharRAJ2000[6] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[9/10] Degree of Declination (J2000)pos.eq.dec;meta.mainVc[11.25/17.49] Cousins V band magnitude (1)magphot.mag;em.opt.VfloatEW(Li)[0.102/0.792] Equivalent width of the LiI {lambda}6708 doublet blended with adjacent neutral iron lines, in Angstroms ({AA})0.1nmspect.line.eqWidthfloatEW(Li)c[0.094/0.765] Deblended equivalent width of the LiI {lambda}6708 doublet, in Angstroms ({AA})0.1nmspect.line.eqWidthfloatA(Li)[-0.78/3.93] Lithium abundancephys.abundfloatEW(Ha)[-63.831/5.4]? Equivalent width of H{alpha} {lambda}, in Angstroms ({AA})0.1nmspect.line.eqWidthfloatnullableHa10[53.5/575.1]? Full width at 10% of peak H{alpha} fluxkm/sspect.line.eqWidthfloatnullableEW(HeI)[-1.595/0.243]? Equivalent width of HeI {lambda}6678, in Angstroms ({AA})0.1nmspect.line.eqWidthfloatnullableS08Display data from Sung et al. (2008, Cat. J/AJ/135/441)meta.ref.urlintnullableSimbadNameSimbad column added by the CDSmeta.idcharnullable