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Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters
The availability of the Hipparcos Catalogue has triggered many kinematicand dynamical studies of the solar neighbourhood. Nevertheless, thosestudies generally lacked the third component of the space velocities,i.e., the radial velocities. This work presents the kinematic analysisof 5952 K and 739 M giants in the solar neighbourhood which includes forthe first time radial velocity data from a large survey performed withthe CORAVEL spectrovelocimeter. It also uses proper motions from theTycho-2 catalogue, which are expected to be more accurate than theHipparcos ones. An important by-product of this study is the observedfraction of only 5.7% of spectroscopic binaries among M giants ascompared to 13.7% for K giants. After excluding the binaries for whichno center-of-mass velocity could be estimated, 5311 K and 719 M giantsremain in the final sample. The UV-plane constructed from these datafor the stars with precise parallaxes (σπ/π≤20%) reveals a rich small-scale structure, with several clumpscorresponding to the Hercules stream, the Sirius moving group, and theHyades and Pleiades superclusters. A maximum-likelihood method, based ona Bayesian approach, has been applied to the data, in order to make fulluse of all the available stars (not only those with precise parallaxes)and to derive the kinematic properties of these subgroups. Isochrones inthe Hertzsprung-Russell diagram reveal a very wide range of ages forstars belonging to these groups. These groups are most probably relatedto the dynamical perturbation by transient spiral waves (as recentlymodelled by De Simone et al. \cite{Simone2004}) rather than to clusterremnants. A possible explanation for the presence of younggroup/clusters in the same area of the UV-plane is that they have beenput there by the spiral wave associated with their formation, while thekinematics of the older stars of our sample has also been disturbed bythe same wave. The emerging picture is thus one of dynamical streamspervading the solar neighbourhood and travelling in the Galaxy withsimilar space velocities. The term dynamical stream is more appropriatethan the traditional term supercluster since it involves stars ofdifferent ages, not born at the same place nor at the same time. Theposition of those streams in the UV-plane is responsible for the vertexdeviation of 16.2o ± 5.6o for the wholesample. Our study suggests that the vertex deviation for youngerpopulations could have the same dynamical origin. The underlyingvelocity ellipsoid, extracted by the maximum-likelihood method afterremoval of the streams, is not centered on the value commonly acceptedfor the radial antisolar motion: it is centered on < U > =-2.78±1.07 km s-1. However, the full data set(including the various streams) does yield the usual value for theradial solar motion, when properly accounting for the biases inherent tothis kind of analysis (namely, < U > = -10.25±0.15 kms-1). This discrepancy clearly raises the essential questionof how to derive the solar motion in the presence of dynamicalperturbations altering the kinematics of the solar neighbourhood: doesthere exist in the solar neighbourhood a subset of stars having no netradial motion which can be used as a reference against which to measurethe solar motion?Based on observations performed at the Swiss 1m-telescope at OHP,France, and on data from the ESA Hipparcos astrometry satellite.Full Table \ref{taba1} is only available in electronic form at the CDSvia anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/430/165}
| Faint Blue Objects at High Galactic Latitude. VIII. Performance Characteristics of the US Survey
The US survey has cataloged 3987 objects in seven high Galactic latitudefields according to their optical colors, magnitudes, and morphologiesusing photographic techniques. This paper analyzes the effectiveness ofthe survey at producing finding lists for complete samples of hot starsand quasars that exhibit blue and/or ultraviolet excess (B-UVX) relativeto the colors of halo F and G subdwarf stars. A table of 599spectroscopic identifications summarizes the spectroscopic coverage ofthe US objects that has been accomplished to date. In addition, some ofthe survey plates have been reexamined for objects missed during theoriginal selection, and the literature has been searched for all otherspectroscopically identified blue stars and quasars with z<2.2 thathave been selected by other surveys within the US survey areas. Theseresults are used to estimate empirically both the accuracy of the USsurvey selection boundaries (in color, morphology, and brightness) andthe completeness of the resulting samples of B-UVX US objects withinthose boundaries. In particular, it is shown that the reliability of theUS color classifications is high and that the previously derived USmorphological boundary for the complete selection of unresolved quasarsis accurate. The contribution of color and morphological classificationerrors to B-UVX sample incompleteness is therefore correspondinglysmall. The empirical tests indicate high levels of completeness(95+1-2%) for the samples of US quasars and hotstars isolated within the stated survey selection limits. Errata andimprovements to some of the published catalog data are presented inAppendices.
| Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Subtittle: Radial velocities: The Wilson-Evans-Batten catalogue.
We give a common version of the two catalogues of Mean Radial Velocitiesby Wilson (1963) and Evans (1978) to which we have added the catalogueof spectroscopic binary systems (Batten et al. 1989). For each star,when possible, we give: 1) an acronym to enter SIMBAD (Set ofIdentifications Measurements and Bibliography for Astronomical Data) ofthe CDS (Centre de Donnees Astronomiques de Strasbourg). 2) the numberHIC of the HIPPARCOS catalogue (Turon 1992). 3) the CCDM number(Catalogue des Composantes des etoiles Doubles et Multiples) byDommanget & Nys (1994). For the cluster stars, a precise study hasbeen done, on the identificator numbers. Numerous remarks point out theproblems we have had to deal with.
| UBVRI photometry of FKSZ stars. IV
The paper presents UBVRI photometry, in the Kron-Cousins system, for 117stars of the Catalog of Fundamental Faint Stars in the declination zone+18-0 deg. The observations were performed from July 1988 to March 1990with the ESO 0.50-m telescope at the ESO in La Silla, Chile. The resultsof 24 nights of observations are reported.
| Photoelectric radial velocities. IV. 528 7 to 10 mag stars in the +15degree selected areas.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971MNRAS.155....1G&db_key=AST
| UBV sequences in selected star fields
Not Available
| Etude photométrique de quelques séquences stellaires par la méthode de Fabry
Not Available
| Etudes photométriques par la méthode de Fabry
Not Available
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Observation and Astrometry data
| Constellation: | Bärenhüter |
| Right ascension: | 14h19m26.34s |
| Declination: | +14°56'08.6" |
| Apparent magnitude: | 8.343 |
| Distance: | 793.651 parsecs |
| Proper motion RA: | 2.9 |
| Proper motion Dec: | 7.9 |
| B-T magnitude: | 10.204 |
| V-T magnitude: | 8.497 |
Catalogs and designations:
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