J/A+A/483/253ivo://CDS.VizieR/J/A+A/483/253doi:10.26093/cds/vizier.34830253CDSMessina S.Distefano D.Padmakar P.Kang Y.B.Kim S.-L.Rey S.-C.,Lee C.-U2008-06-21T22:54:16Z2008-06-21T22:52:06ZCDS support team

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

cds-question@unistra.fropen-star-clusterseclipsing-binary-starsvisible-astronomybroad-band-photometryRotation and solar-type magnetic activity are closely related to each other in main-sequence stars of G or later spectral types. The presence and level of magnetic activity depend on star's rotation, and rotation itself is strongly influenced by strength and topology of the magnetic fields. Open clusters represent especially useful targets to investigate the connection between rotation and activity. The open cluster NGC 2099 has been studied as a part of the RACE-OC project (Rotation and ACtivity Evolution in Open Clusters), which is aimed at exploring the evolution of rotation and magnetic activity in the late-type members of open clusters of different ages. We collected time series CCD photometric observations of this cluster in January 2004, and we determined the presence of periodicities in the flux variation related to the stellar rotation by Fourier analysis. We investigate the relations between activity manifestations, such as the light curve amplitude, and global stellar parameters. We have discovered 135 periodic variables, 122 of which are candidate cluster members. Determination of rotation periods of G- and K-type stars has allowed us to better explore the evolution of angular momentum at an age of about 500Myr. In our analysis, we have also identified 3 new detached eclipsing binary candidates among cluster members. A comparison with the older Hyades cluster (~625Myr) shows that the newly-determined distribution of rotation periods is consistent with the scenario of rotational braking of main-sequence spotted stars as they age. However, a comparison with the younger M34 cluster (~200Myr) shows that the G8-K5 members of these clusters have the same rotation period distribution. That is, G8-K5 members in NGC 2099 seem to have experienced no significant braking in the age range from ~200 to ~500Myr. Finally, NGC 2099 members have a smaller level of photospheric magnetic activity, as measured by light curve amplitude, than in younger stars of the same mass and rotation, suggesting that the activity level also depends on some other age-dependent parameters.2008A&A...483..253Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/483/253CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/480/495 : Patterns of color variations in close binaries (Messina, 2008)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/483/253https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/483/253http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/483/253https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/483/253https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/483/253http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/483/253GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/483/253/table1 (Summary of photometric observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/483/253/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/483/253/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/483/253/table1?GETtext/xml+votable180.050000true88.04702532.569738890.0055555555555555566/24520 24522https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/483/253?format=asciiOpticaldefaultJ/A+A/483/253/table2Summary of correlation and regression analysesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTargetTarget's Identification Numbermeta.id;meta.mainintPScarglePeriod from Scargle analysisdtime.periodfloatPcleanPeriod from CLEAN analysisdtime.periodfloatPnormNormalized power from Scargle periodogramtime.periodfloatPerAdopted perioddtime.periodfloate_PerUncertainty on the adopted perioddstat.errorfloato_VmeanNumber of observationsmeta.numberintVmeanMean V magnitudemagphot.mag;em.opt.Vfloate_VmeanV-magnitude standard deviationmagstat.errorfloatVaccV-band photometric accuracymagstat.errorfloatVampV-band light curve amplitudemagphot.mag;em.opt.VfloatNoteNote on membership and variable type (1)meta.notecharKangName in Kang et al. (2007PASP..119..239K) for already known variablesmeta.idcharJ/A+A/483/253/table1Summary of photometric observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTargetTarget's Identification Numbermeta.id;meta.mainintprimaryn_Target[*] indicates light curve in table3meta.notecharRAJ2000Right ascension (J2000.0)pos.eq.ra;meta.mainDEJ2000Declination (J2000.0)pos.eq.dec;meta.main(Vmag)0Dereddened V magnitudemagphot.mag;em.opt.Vfloat(B-V)0Dereddened (B-V) colour indexmagphot.color;em.opt.B;em.opt.VfloatLCPlot of the LCmeta.ref.urlchar