J/AN/329/801ivo://CDS.VizieR/J/AN/329/801doi:10.26093/cds/vizier.113290801CDSCaballero J.A.Dinis L.2025-09-29T20:17:41Z2009-03-07T22:04:17ZCDS support team

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

cds-question@unistra.frstellar-associationsearly-type-starsproper-motionsWe study the spatial structure and sub-structure of regions rich in Hipparcos stars with blue BT-VT colours. These regions, which comprise large stellar complexes, OB associations, and young open clusters, are tracers of on-going star formation in the Galaxy. The DBSCAN (Density-Based Spatial Clustering of Applications with Noise) data clustering algorithm is used to look for spatial overdensities of early-type stars. Once an overdensity, "agglomerate", is identified, we carry out a data and bibliographic compilation of their star member candidates. The actual membership in agglomerate of each early-type star is studied based on its heliocentric distance, proper motion, and previous spectro-photometric information. We identify 35 agglomerates of early-type Hipparcos stars. Most of them are associated to previously known clusters and OB associations. The previously unknown P Puppis agglomerate is subject of a dedicated study with Virtual Observatory tools.2008AN....329..801Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AN/329/801CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/239 : The Hipparcos and Tycho Catalogues (ESA 1997)I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AN/329/801https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AN/329/801http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AN/329/801https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AN/329/801https://vizier.iucaa.in/viz-bin/votable?-source=J/AN/329/801http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AN/329/801GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AN/329/801/table1 (Agglomerates of early-type Hipparcos stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AN/329/801/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AN/329/801/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AN/329/801/table1?GETtext/xml+votable180.050000true43.62229.07430.005555555555555556Cone search capability for table J/AN/329/801/tablea1 (Early-type Hipparcos stars in aggregates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AN/329/801/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/AN/329/801/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AN/329/801/tablea1?GETtext/xml+votable180.050000true56.218916724.11333330.0055555555555555565/5189-5190 5414 5514 5715 5723 9798 9804 9965-9967 6/148 461 463 472 474 496 13559 13730 14645 14688-14689 14691 20753 20764 20766-20767 20789 20800-20801 20808 20810-20811 20832-20834 20836 21432 21434-21436 21438-21439 21482 21528-21530 21645 22051 22805 22837 22849-22851 22854 22858-22859 22874 22880-22881 22884-22885 22887 22889 22898 22904 22906-22907 22981 23010-23011 23637 23639 37787 37790 37864-37865 37867 39181 39183 39196 39198 39205 39207 39211 39220 39235 39241 39243-39244 39249 39251 39254 39296-39297 39299 39343 39354-39355 39372 39374-39375 39397 39685 39696 39737-39740 39791 39802 39815 39825 39827 39832-39833 39857-39859 39877-39878 39881-39884 39886 39890-39891 39896-39897 39904 39906-39908 39910 39913-39914 39916 39918https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AN/329/801?format=asciiOpticaldefaultJ/AN/329/801/table1Agglomerates of early-type Hipparcos starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEscorialAgglomerate designation (Escorial NN)meta.id;meta.mainintprimaryStarReference starmeta.id.assoccharGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latSup-AgglSuper-Agglomerate designationmeta.id.parentcharAssocCluster/Association/Complex/Regionmeta.id.parentcharNstarNumber of star in the agglomeratemeta.numberintContPossible contaminant(s)meta.notechar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexedJ/AN/329/801/tablea1Early-type Hipparcos stars in aggregatesNameOther namemeta.idcharn_pmDE[)] Difference in pmDE (2)meta.notecharSpTypeMK spectral typesrc.spTypecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEscorialAgglomerate designation (Escorial NN)meta.id.parentintHIPHIP numbermeta.id;meta.mainintDist? Heliocentric distancepcpos.distanceintnullablee_Dist? rms uncertainty on Distpcstat.errorintnullablen_Dist[:h] Note on Dist (1)meta.notecharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainpmRA? Proper motion along RA, pmRA*cosDEmas/yrpos.pm;pos.eq.rafloatnullablee_pmRA? rms uncertainty on pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatnullablen_pmRA[)] Difference in pmRA (2)meta.notecharpmDE? Proper motion along DEmas/yrpos.pm;pos.eq.decfloatnullablee_pmDE? rms uncertainty on pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatnullableSimbadSimbad column added by the CDSmeta.refchar