J/ApJ/912/5ivo://CDS.VizieR/J/ApJ/912/5doi:10.26093/cds/vizier.19120005CDSHu Q.Zhang Y.Esamdin A.Liu J.Zeng X.2022-05-17T12:21:31Z2021-05-28T09:12:10ZCDS support team

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

cds-question@unistra.fropen-star-clustersWe analyze the morphological evolution of open clusters and provide shape parameters for 265 open clusters. The results show that the overall shape of sample clusters becomes more elliptical as they grow older, while their core remains circular or slightly trending to circular. There is a negative correlation of the ellipticities with the number of members of the sample clusters. A significant negative correlation between the overall ellipticities and masses is also detected for the sample clusters with log(age/year)>=8, suggesting that the overall shapes of the clusters are possibly influenced by the number of members and masses, in addition to the external forces and the surrounding environment. For most young sample clusters, the radial stratification degree of the short-axis direction is greater than that of the long, implying that the radial stratification degree in the two directions within the young sample cluster may be unevenly affected by an internal evolutionary process. Older sample clusters exhibit lower stratification in the tangential direction, which possibly means those clusters may continue to survive for a long time at a low level of stratification. Our analysis shows that the overall shape of the sample clusters may be more susceptible to the influence of Galactic tides toward the Galactic center than the shear forces embedded in Galactic differential rotation. By analyzing the distribution of the ages and number of members of star clusters, we suggest that NGC 6791 may originate from superclusters.2021ApJ...912....5Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/912/5CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/618/A93 : Gaia DR2 open clusters in the Milky Way (Cantat-Gaudin+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/912/5https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/912/5http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/912/5https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/912/5https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/912/5http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/912/5GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/912/5/table1 (The parameters of 265 open clusters in this paper)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/912/5/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/912/5/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/912/5/table1?GETtext/xml+votable180.050000true51.8695134.981290.0055555555555555566/463 1101 1119 1302 1347 1423 1461 1464 1482 1576 1794 1923 1930 1948 2395 2436 2859 3038 3050 3136 3170 3186 3227 3230 3289 3298 3556 3595 3622-3623 3712 3739 3796 4078 4298 4698 6149 6307 6760 6881 12955 12990 13096 13198 13952 13962 14033 14058 14076 14098 14162 14182 14210 14221 14223 14288 14295 14346 14363 14373 14410 14553 14571 14575 14689 14732 14749 14752 14878 15121 15369 15379 15432 15449 15520 15622 15632 20797 20823 20833 20853-20854 20966 21369 21495 21513 21520 21529 21531 21540 21549 21557 21561 21606 21647 21656 21658 21682 21694 21927 22021 22032 22037 22094 22112 22121 22163 22183 22408 22880 22895 22993 23410 23626 23633 23663 23936 24291 24329 24344-24345 24476 24510 24527 28709 28711 28838 28916 29027 29032 29081 29269 29777 29868 30232 30439 30635 31790 31812 31853 31865 32111 33102 37231 37236 37297 37326 37332 37348-37349 37592 37705 37724 37737 37745 37753 37789-37790 37892 37920 37926 37928-37929 37933 38018 38023 38041 38051 38073 38432 38539 39005 39181 39191 39216 39233 39237 39244-39245 39251 39290 39354-39355 39374 39385 39397 39406 39420 39423 39709 39739 39763 39774-39775 39785 39789 39797 39805 39867 39871 39894-39895 39900 39920 39931 39956 40071 40104 40451 40490 40610 40612 40616 40620 41445 41455 41461 41466 41557-41558 41599 41620 41633 41646 41670 41675 41682 41688 41692 41703 41710 41768 41770 41834 41846 41878 41995 42029 42135 42150 42159 42164 42170 42203 42353 42364 42377 42402 42420 42548 43022 43024 43036 43044 43047-43048 43301 47621https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/912/5?format=asciidefaultJ/ApJ/912/5/table1The parameters of 265 open clusters in this paperSimbadNameSimbad column added by the CDSmeta.idcharHHeight from Galactic diskpcpos.cartesian.z;pos.galacticfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameCluster identifiermeta.id;meta.maincharGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latlogAgelog cluster agelog(yr)time.agefloatNumNumber of member stars in clustermeta.numberfloateCoreCore ellipticitysrc.ellipticityfloate_eCoreUncertainty in eCorestat.errorfloatqCoreCore orientationdegpos.posAngfloateAllEllipticity of entire clustersrc.ellipticityfloate_eAllUncertainty in eAllstat.errorfloatqAllEntire cluster orientationdegpos.posAngfloataCoreCore half-lengthphys.sizefloatbCoreCore half-short axisphys.sizefloataAllEntire cluster half-lengthphys.sizefloatbAllEntire cluster half-short axisphys.sizefloat_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.decnullableindexed