J/A+A/624/L11ivo://CDS.VizieR/J/A+A/624/L11doi:10.26093/cds/vizier.36249011CDSFuernkranz V.Meingast S.Alves J.2020-02-21T09:00:44Z2019-04-23T08:59:24ZCDS support team

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

cds-question@unistra.fropen-star-clustersastrometryWe report the discovery of a kinematically cold group of stars, located in the immediate neighborhood of the well-known star cluster Coma Berenices (Mel 111). The new group identified in tangential velocity space as measured by Gaia contains at least 177 coeval members distributed in two subgroups, and appears as a flattened structure parallel to the plane, stretching for about 50pc. More remarkably, the new group, which appears to have formed about 300Myr later than Mel 111 in a different part of the Galaxy, will share essentially the same volume with the older cluster when the centers of both groups will be at their closest in 13 Myr. This will result in the mixing of two unrelated populations with different metallicities. The phase of cohabitation for these two groups is about 20-30Myr, after which the two populations will drift apart. We estimate that temporal cohabitation of such populations is not a rare event in the disk of the Milky Way, and of the order of once per Galactic revolution. Our study also unveils the tidal tails of the Mel 111 cluster.2019A&A...624L..11Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/624/L11CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)J/A+A/621/L3 : Hyades tidal tails with Gaia DR2 (Meingast+, 2019)J/A+A/622/L13 : Stellar stream in Gaia DR2 discovery (Meingast+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/624/L11https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/624/L11http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/624/L11https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/624/L11https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/624/L11http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/624/L11GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/624/L11/coma_ber (Member selection for Coma Berenices (table A2))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/624/L11/coma_ber?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/624/L11/coma_ber?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/624/L11/coma_ber?GETtext/xml+votable180.050000true195.8597763925.652398090.005555555555555556Cone search capability for table J/A+A/624/L11/coma_nei (Member selection for neighbor group (table A2))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/624/L11/coma_nei?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/624/L11/coma_nei?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/624/L11/coma_nei?GETtext/xml+votable180.050000true235.0594387353.5257060.0055555555555555565/2686 2769 2772 2843 2859 7023 7032 7111 7120-7122 6/8948 8952-8953 8957 9131 9134 9184 10276 10286 10289-10290 10292 10298 10338 10342 10356 10361 10364 10369-10370 10387 10397 10409 10417 10419 10427 10429 10431-10432 10434 10448 10455 10468 10470 10477-10478 10503 10517 10521 10540 10543 10582 10594 10630 10639 10646 10653 10662 10684 10694 10703 10706 10710-10711 10715-10717 10724 10726 10732 10741 10743 10749 10787 11011 11025 11027 11029 11031 11039 11083 11087 11094 11096-11097 11099 11103 11105 11107 11109 11111 11132 11221 11317 11323 11346 11350 11355-11356 11364-11365 11367 11378-11379 11392-11394 11400 11402 11406 11408 11410 11412 11417 11419 11421 11424 11426 11430-11431 11444 11446 11449 11451 11453-11454 11460 11462-11463 11467 11470-11471 11473-11476 11478 11482 11489-11492 11494 11498-11500 11502 11510-11512 11515-11516 11554 11562 11680 11779 11782 11789 11795 11798 11800 11804 11809 11815 11818 11835 11841 11844 11848 11852 11860 11872 11911 27773 27834 27860 27895 27983 27996 28010 28022 28027 28071-28072 28078-28079 28085 28087 28100 28108 28112 28116 28118 28123 28125 28127 28133-28134 28136-28138 28140-28141 28144 28150-28154 28156 28177 28188-28189 28213 28227 28244 28265 28270 28272 28286 28367 28376-28377 28416 28425 28431-28433 28439-28442 28452-28453 28455 28457 28467 28469-28470 28492 28494-28496 28498-28500 28502 28504 28506 28509 28515-28516 28526 28537 28555 28560 28608https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/624/L11?format=asciidefaultJ/A+A/624/L11/coma_berMember selection for Coma Berenices (table A2)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceGaia DR2 Unique source identifiermeta.id;meta.mainRA_ICRSGaia DR2 Right ascension (ICRS) at epoch 2015.5degpos.eq.ra;meta.mainDE_ICRSGaia DR2 Declination (ICRS) at epoch 2015.5degpos.eq.dec;meta.mainPlxGaia DR2 parallaxmaspos.parallaxdoublepmRA*Gaia DR2 Proper motion in RA direction, pmRA*cosDEmas/yrpos.pm;pos.eq.radoublepmDEGaia DR2 Proper motion in DE directionmas/yrpos.pm;pos.eq.decdoubleRV? Gaia DR2 Radial velocitykm/sphys.veloc;pos.heliocentricdoublenullableXGalactic Cartesian Xpcpos.cartesian.x;pos.galacticfloatYGalactic Cartesian Ypcpos.cartesian.y;pos.galacticfloatZGalactic Cartesian Zpcsrc.redshift;pos.galactic;pos.cartesianfloatvRAVelocity along RAkm/sphys.velocfloatvDEVelocity along DEkm/sphys.velocfloatvR? Galactocentric Cylindrical vRkm/sphys.velocfloatnullablevPHI? Galactocentric Cylindrical vPHIkm/sphys.velocfloatnullablevZ? Galactocentric Cylindrical vZkm/sphys.veloc;pos.cartesian.zfloatnullable_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.decnullableindexedJ/A+A/624/L11/coma_neiMember selection for neighbor group (table A2)vZ? Galactocentric Cylindrical vZkm/sphys.veloc;pos.cartesian.zfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceGaia DR2 Unique source identifiermeta.id;meta.mainRA_ICRSGaia DR2 Right ascension (ICRS) at epoch 2015.5degpos.eq.ra;meta.mainDE_ICRSGaia DR2 Declination (ICRS) at epoch 2015.5degpos.eq.dec;meta.mainPlxGaia DR2 parallaxmaspos.parallaxdoublepmRA*Gaia DR2 Proper motion in RA direction, pmRA*cosDEmas/yrpos.pm;pos.eq.radoublepmDEGaia DR2 Proper motion in DE directionmas/yrpos.pm;pos.eq.decdoubleRV? Gaia DR2 Radial velocitykm/sphys.veloc;pos.heliocentricdoublenullableXGalactic Cartesian Xpcpos.cartesian.x;pos.galacticfloatYGalactic Cartesian Ypcpos.cartesian.y;pos.galacticfloatZGalactic Cartesian Zpcsrc.redshift;pos.galactic;pos.cartesianfloatvRAVelocity along RAkm/sphys.velocfloatvDEVelocity along DEkm/sphys.velocfloatvR? Galactocentric Cylindrical vRkm/sphys.velocfloatnullablevPHI? Galactocentric Cylindrical vPHIkm/sphys.velocfloatnullable_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.decnullableindexed