Proper motion determination of open clusters based on the UCAC2 catalogue
We present the kinematics of hundreds of open clusters, based on theUCAC2 Catalogue positions and proper motions. Membership probabilitieswere obtained for the stars in the cluster fields by applying astatistical method uses stellar proper motions. All open clusters withknown distance were investigated, and for 75 clusters this is the firstdetermination of the mean proper motion. The results, including the DSSimages of the cluster's fields with the kinematic members marked, areincorporated in the Open Clusters Catalogue supported on line by ourgroup.
|
Astrophysical parameters of Galactic open clusters
We present a catalogue of astrophysical data for 520 Galactic openclusters. These are the clusters for which at least three most probablemembers (18 on average) could be identified in the ASCC-2.5, a catalogueof stars based on the Tycho-2 observations from the Hipparcos mission.We applied homogeneous methods and algorithms to determine angular sizesof cluster cores and coronae, heliocentric distances, mean propermotions, mean radial velocities, and ages. For the first time we derivedistances for 200 clusters, radial velocities for 94 clusters, and agesof 196 clusters. This homogeneous new parameter set is compared withearlier determinations, where we find, in particular, that the angularsizes were systematically underestimated in the literature.
|
Proper Motions of Open Star Clusters and the Rotation Rate of the Galaxy
The mean proper motions of 167 Galactic open clusters withradial-velocity measurements are computed from the data of the Tycho-2catalog using kinematic and photometric cluster membership criteria. Theresulting catalog is compared to the results of other studies. The newproper motions are used to infer the Galactic rotation rate at the solarcircle, which is found to be ω0=+24.6±0.8 km s-1 kpc-1.Analysis of the dependence of the dispersion of ω0 estimates onheliocentric velocity showed that even the proper motions of clusterswith distances r>3 kpc contain enough useful information to be usedin kinematic studies demonstrating that the determination of propermotions is quite justified even for very distant clusters.
|
Proper motions of open clusters within 1 kpc based on the TYCHO2 Catalogue
We present mean absolute proper motions of 112 open clusters, determinedusing the data from the Tycho2 Catalogue. For 28 clusters, this is thefirst determination of proper motion. The measurements made use of alarge number of stars (usually several tens) for each cluster. The totalnumber of stars studied in the fields of the 164 open clusters is 5016,of which 4006 were considered members. The mean proper motions of theclusters and membership probability of individual stars were obtainedfrom the proper motion data by applying the statistical method proposedby Sanders (\cite{Sanders71}). Based on observations of the ESAHipparcos satellite. Tables 1, 2 and 5 to 117 are only available inelectronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr(130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/376/441
|
Absolute proper motions of open clusters. I. Observational data
Mean proper motions and parallaxes of 205 open clusters were determinedfrom their member stars found in the Hipparcos Catalogue. 360 clusterswere searched for possible members, excluding nearby clusters withdistances D < 200 pc. Members were selected using ground basedinformation (photometry, radial velocity, proper motion, distance fromthe cluster centre) and information provided by Hipparcos (propermotion, parallax). Altogether 630 certain and 100 possible members werefound. A comparison of the Hipparcos parallaxes with photometricdistances of open clusters shows good agreement. The Hipparcos dataconfirm or reject the membership of several Cepheids in the studiedclusters. Tables 1 and 2 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
|
The Evolution of Rotation and Activity in Young Open Clusters: IC 2391
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996ApJS..106..489P&db_key=AST
|
Chemical Evolution of the Galactic Disk: Evidence for a Gradient Perpendicular to the Galactic Plane
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995AJ....110.2813P&db_key=AST
|
Catalogue of blue stragglers in open clusters.
An extensive survey of blue straggler candidates in galactic openclusters of both hemispheres is presented. The blue stragglers wereselected considering their positions in the cluster colour-magnitudediagrams.They were categorized according to the accuracy of thephotometric measurements and membership probabilities. An amount of 959blue straggler candidates in 390 open clusters of all ages wereidentified and classified. A set of basic data is given for everycluster and blue straggler. The information is arranged in the form of acatalogue. Blue stragglers are found in clusters of all ages. Thepercentage of clusters with blue stragglers generally grows with age andrichness of the clusters. The mean ratio of the number of bluestragglers to the number of cluster main sequence stars is approximatelyconstant up to a cluster age of about 10^8.6^ yr and rises for olderclusters. In general, the blue stragglers show a remarkable degree ofcentral concentration.
|
South for the Winter
Not Available
|
Liste des étoiles Ap et Am dans les amas ouverts (Edition révisée)
Not Available
|
Photometric metal abundances of high-luminosity red stars in young and intermediate-age open clusters
UBV, DDO, and Washinton photometry has been obtained for G and K starslocated in or near 22 young and intermediate-age open clusters. Nearly65 percent of the observed stars are found to have a high probability ofbeing cluster members, while the remaining 35 percent are likely to bered field stars. Five clusters (NGC 2383, NGC 3033, Ruprecht 20, NGC5168, and NGC 6249) probably do not contain any red giants. Sixteenclusters are found to be nearly solar in composition; three are slightlymetal-poor or metal-rich; one (Ruprecht 20) is moderately metal-poor(Fe/H = -0.3); and another (NGC 5617) is moderately metal-rich (Fe/H =0.3). None of the clusters with derived Washington abundances appear tobe enriched in elements of the CNO group.
|
Internal kinematics of open star clusters
Proper motion measurements are employed to investigate the internalkinematics of eight open star clusters. In most of the clustersconsidered, no dependence of the intrinsic dispersion in proper motionon stellar mass and radial distance from the cluster center is noted.Velocity isotropy is found in all of the clusters except NGC 2516.
|
Component Analysis of Open Clusters
Not Available
|
The Catalog of Chemically Peculiar Stars in Open Clusters
Not Available
|
Catalog of AP and AM stars in open clusters
The previous results of Raab (1922), Markarian (1951), and Collinder(1931) have been used to catalog Ap and Am stars that are in the fieldof open clusters. Tabular data are presented for the clusterdesignation, the HD or HDE number, the right ascension (1900), thedeclination (1900), and the magnitude. Also listed are the spectraltypes and, for certain stars, the probability of cluster membership.
|
A cluster analysis of open clusters
The Galactic distribution of 361 open clusters is studied using acluster analysis method. It is shown that more than half of the clustersenter groups with characteristic dimensions of several hundred parsecs.To distinguish physical clusters from random condensations, criteriabased on age similarity, the color of the main-sequence blue end, andthe integrated color and radial velocity of the clusters are used. Theproximity of these values suggests a physical unity and common origin ofclusters in a group.
|
Chemically peculiar stars in open clusters. I - The catalog
The largest existing compilation is presented of Ap and Am open clusterstars. The catalog contains information on 381 chemically peculiar (CP)stars of the upper main sequence in 79 open clusters. The catalog iscomposed of the following tables: (1) the main body, which lists CP (orsuspected CP) stars which are kinematical (or suspected kinematical)members of open clusters; (2) the list of CP (or suspected CP) starssometimes numbered among cluster members but which are actuallykinematical nonmembers; (3) the list of stars sometimes designated as'peculiar' but, in fact, probably not CP; (4) references for numberingsystems of cluster stars; (5) references for membership; and (6)references for spectral and/or peculiarity types.
|
A cluster analysis of young open clusters
Cluster analysis methods are used to consider the galactic distributionof 224 open clusters with an age up to 10 to the 8th yrs. Most of theseclusters enter condensations with characteristic dimensions of a fewhundred parsecs. Some condensations are so similar in terms of the age,integrated color, and radial velocity of their components, that thiscannot be considered a coincidence. This suggests that each condensationis a physical entity consisting of clusters apparently linked by acommon origin.
|
Catalogue of UBV Photometry and MK Spectral Types in Open Clusters (Third Edition)
Not Available
|
Proper motion studies of stars in and around open clusters
A compilation of proper motion studies of stars in and around openclusters is presented. It can serve as a reference to cluster memberselections, studies of cluster dynamics, or as a guide to furtherimprovement of the data presently available. The present paper is only apreliminary version.
|
Open clusters and galactic structure
A total of 610 references to 434 clusters are employed in thecompilation of a catalog of open clusters with color-magnitude diagramson the UBV or RGU systems. Estimates of reddening, distance modulus, ageand number of cluster members are included. Although the sample isconsidered representative of the discoverable clusters in the galaxy,the observed distribution is nonuniform because of interstellarobscuration. Cluster distribution in the galactic plane is found to bedominated by the locations of dust clouds rather than by spiralstructure. The distributions of clusters as a function of age andrichness class show that the lifetimes of poor clusters are much shorterthan rich ones, and that clusters in the outer disk survive longer thanthose in the inner disk. An outer disk age which is only about 50% theage of the globular clusters is indicated by cluster statistics. Thethickening of the galactic disk with increasing galactocentric distancemay be due to either a younger dynamical age or a lower gravitationalpotential in the outer regions.
|
Analysis of the results of MK classification of 176 stars in 37 southern open clusters
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1979A&AS...37..345F&db_key=AST
|
A catalogue of galactic clusters observed in three colours
This catalogue contains photometric data for 190 galactic clusters, allobserved in UBV or RGU. The distances of the young clusters (with spless than b3) have been calculated or recalculated according to method Aof Becker (1963). The galactic distribution of these clusters confirmstheir role of being good spiral tracers.
|
Southern open clusters II. UBV and Hbeta photometry of 11 clusters between galactic longitudes 259d and 280d
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973A&AS....9...97V&db_key=AST
|
