J/ApJ/877/12ivo://CDS.VizieR/J/ApJ/877/12doi:10.26093/cds/vizier.18770012CDSTang S.-Y.Pang X.Yuan Z.Chen W.P.Hong J.Goldman B.Just A.,Shukirgaliyev B.Lin C.-C.2021-02-23T12:02:24Z2019-06-03T09:57:32ZCDS support team

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

cds-question@unistra.fropen-star-clustersvisible-astronomytrigonometric-parallaxproper-motionsradial-velocityWe report the discovery of tidal structures around the intermediate-aged (~700-800Myr), nearby (~85pc) star cluster Coma Berenices. The spatial and kinematic grouping of stars is determined with the Gaia DR2 parallax and proper motion data, by a clustering analysis tool, StarGO, to map 5D parameters (X, Y, Z, {mu}_{alpha}*cos{delta}, {mu}_{delta}_) onto a 2D neural network. A leading and a trailing tails, each with an extension of ~50pc are revealed for the first time around this disrupting star cluster. The cluster members, totaling to ~115^+5^_-3_M_{sun}_, are clearly mass segregated, and exhibit a flat mass function with {alpha}~0.79+/-0.16, in the sense of dN/dm{prop.to}m^-{alpha}^, where N is the number of member stars and m is stellar mass, in the mass range of m=0.25-2.51M_{sun}_. Within the tidal radius of ~6.9pc, there are 77 member candidates with an average position, i.e., as the cluster center, of RA=186.8110{deg}, and DE=25.8112{deg}, and an average distance of 85.8pc. Additional 120 member candidates reside in the tidal structures, i.e., outnumbering those in the cluster core. The expansion of escaping members lead to an anisotropy in the velocity field of the tidal tails. Our analysis also serendipitously uncovers an adjacent stellar group, part of which has been cataloged in the literature. We identify 218 member candidates, 10 times more than previously known. This star group is some 65pc away from, and ~400Myr younger than, Coma Ber, but is already at the final stage of disruption.2019ApJ...877...12Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/877/12CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/877/12https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/877/12http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/877/12https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/877/12https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/877/12http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/877/12GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/877/12/table1 (Coma Ber Member Candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/877/12/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/877/12/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/877/12/table1?GETtext/xml+votable180.050000true183.1036680627.380058060.005555555555555556Cone search capability for table J/ApJ/877/12/table2 (Group-X Member Candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/877/12/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/877/12/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/877/12/table2?GETtext/xml+votable180.050000true178.9487661139.073363060.0055555555555555565/2686 2769 2843 2859 2868 7023 7120 7121 7122 6/8727 8907 8948 8952 8953 8957 9103 9134 9851 9943 9969 9976 9979 9982 9983 10018 10145 10276 10286 10290 10292 10298 10334 10356 10361 10364 10369 10370 10387 10397 10409 10417 10419 10427 10429 10434 10448 10455 10468 10477 10478 10503 10517 10540 10543 10560 10562 10646 10653 10662 10684 10694 10703 10710 10711 10715 10716 10717 10724 10726 10741 10743 10748 10749 10787 10877 10885 10914 11011 11025 11029 11031 11039 11044 11051 11057 11087 11088 11089 11090 11094 11096 11097 11099 11103 11105 11107 11109 11111 11115 11126 11132 11133 11142 11205 11221 11323 11333 11343 11345 11346 11347 11348 11350 11351 11353 11355 11356 11358 11361 11364 11365 11367 11378 11379 11382 11392 11393 11394 11400 11402 11406 11408 11410 11412 11417 11419 11421 11424 11426 11430 11431 11444 11446 11449 11451 11453 11454 11459 11460 11462 11463 11467 11469 11470 11471 11476 11478 11482 11489 11490 11491 11492 11494 11498 11499 11500 11502 11503 11511 11512 11515 11516 11562 11680 11691 11716 11779 11782 11789 11790 11795 11798 11800 11809 11815 11818 11832 11835 11841 11844 11848 11853 11872 26286 26330 26591 26619 26999 27135 27773 27783 27797 27821 27834 27860 27879 27895 27974 27983 27996 28010 28022 28027 28071 28072 28078 28079 28085 28087 28100 28108 28112 28116 28118 28123 28125 28127 28129 28130 28131 28133 28134 28136 28137 28138 28140 28141 28144 28150 28151 28152 28153 28154 28156 28177 28188 28189 28198 28213 28227 28265 28270 28272 28286 28287 28295 28316 28376 28377 28416 28425 28431 28433 28439 28440 28441 28442 28444 28445 28446 28452 28453 28455 28457 28467 28469 28470 28494 28495 28496 28498 28500 28502 28504 28506 28509 28515 28516 28537 28555 28560 28608 286671.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/877/12?format=asciiOpticaldefaultJ/ApJ/877/12/table1Coma Ber Member CandidatesSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/197] Coma Ber member candidate, running numbermeta.id;meta.mainintRA_ICRSRight Ascension (ICRS) at epoch 2015.5 (G1)degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at epoch 2015.5 (G1)degpos.eq.dec;meta.mainPlxParallax (G1)maspos.parallaxfloate_PlxUncertainty in Plx (G1)masstat.error;pos.parallaxfloatpmRAProper motion in Right Ascension, pmRA*cosDE (G1)mas/yrpos.pm;pos.eq.rafloate_pmRAUncertainty in pmRA (G1)mas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion in Declination (G1)mas/yrpos.pm;pos.eq.decfloate_pmDEUncertainty in pmDEc (G1)mas/yrstat.error;pos.pm;pos.eq.decfloatRV? Radial Velocity (G1)km/sphys.veloc;pos.heliocentricfloatnullablee_RV? Uncertainty in RV (G1)km/sstat.errorfloatnullableGmagGaia G band magnitude (G1)magphot.mag;em.optfloatMemb[bt] Membership flag (2)meta.code.errorcharGaiaDR2Display the Gaia DR2 data (Gaia Collaboration, 2018, Cat. I/345)meta.ref.urlchar_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/ApJ/877/12/table2Group-X Member CandidatesSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/218] Group-X candidate, running numbermeta.id;meta.mainintRA_ICRSRight Ascension (ICRS) at epoch 2015.5 (G1)degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at epoch 2015.5 (G1)degpos.eq.dec;meta.mainPlxParallax (G1)maspos.parallaxfloate_PlxUncertainty in Plx (G1)masstat.error;pos.parallaxfloatpmRAProper motion in Right Ascension, pmRA*cosDE (G1)mas/yrpos.pm;pos.eq.rafloate_pmRAUncertainty in pmRA (G1)mas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion in Declination (G1)mas/yrpos.pm;pos.eq.decfloate_pmDEUncertainty in pmDEc (G1)mas/yrstat.error;pos.pm;pos.eq.decfloatRV? Radial Velocity (G1)km/sphys.veloc;pos.heliocentricfloatnullablee_RV? Uncertainty in RV (G1)km/sstat.errorfloatnullableGmagGaia G band magnitude (G1)magphot.mag;em.optfloatGaiaDR2Display the Gaia DR2 data (Gaia Collaboration, 2018, Cat. I/345)meta.ref.urlchar_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