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Wide binaries among high-velocity and metal-poor stars
A catalogue of 122 wide binaries is presented. The list was compiled bysearching for common proper-motion companions to the more than 1200high-velocity and metal-poor stars of Schuster and collaborators. Westudy the separations for the wide binaries (< a> > 25 AU), andfind that they follow Oepik's distribution all the way up to 10 000 AU.A subgroup of them, the ones with the most halo-like orbits, followOepik's distribution up to 20 000 AU. The galactic orbits of all systemsare calculated, and galactic orbital parameters are used, along with themetallicites, to assign each one to the old thin disk, the thick disk,or the halo population. Table~2 is only available in electronic form atthe CDS via anonymous ftp to cdsarc.u.strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| Mesures et decouvertes d'etoiles doubles effectuees a la lunette de 50cm de l'Observatoire de Nice. Measures and discoveries of visual double stars made with the 50cm refractor at the Nice Observatory.
Measures and discoveries of visual double stars made at the Observatoirede la Cote d'Azur at Nice, between 1988 and 1994, with the 50cmrefractor equipped with a filar micrometer and electronic recordingdevice. The programs proposed by J. Dommanget involve the complement ofthe C.C.D.M. (resolving problems of identification of double stars andof coherency in the Index) and the INput CAtalog Hipparcos (resolutionof ambiguities on the binarity and on the position of certain doublestars which have seldom or never been observed again from the epoch ortheir discovery). The author has discovered three new binaries: JCT1,JCT2 and JCT3.
| UVBY - beta photometry of high-velocity and metal-poor stars. VI - A second catalogue, and stellar populations of the Galaxy
A second catalog of uvby-beta photometry for 553 high-velocity stars ispresented. Combining the catalogs, reliable (Fe/H) values are obtainedfor 1214 stars and reliable kinematic parameters for 1149. The totalsample contains at least three significant, distinct stellar populationswith properties very similar to those given in the literature of the oldthin disk, thick disk, and halo. The thick-disk component has mean(Fe/H) about -0.50 +/- 0.10 dex and sigma(Fe/H) about 0.25 +/- 0.03 dex,but there is evidence for a significant thick-disk contribution down to(Fe/H) about -1.4. A diagonal cut in the V(rot), (Fe/H) diagramindicates that there is not a chemical gradient in the Galactic halo.The mean V(rot), mean (Fe/H) curve for the whole sample indicates thatthe halo evolved mostly independently of the disk.
| New subdwarfs. VI - Kinematics of 1125 high-proper-motion stars and the collapse of the Galaxy
The UVW velocity components, planar eccentricities, and angular momentaof 878 high-proper-motion stars are determined using the radial-velocitydata of Fouts and Sandage (1986) and compared with chemical abundancesand photometric parallaxes from the UBV photometry of Sandage and Kowal(1986). The results are presented, along with published data on 247additional stars, in extensive tables and graphs and characterized indetail. Two approximately equal components are differentiated: alow-velocity component identified as part of the thick disk described byGilmore and Reid (1983) and a high-velocity halo component. The data arefound to support a model of Galactic collapse (with concomitant spinupand progressive chemical enrichment) which includes a rotating bulge(the thick disk) with kinematic and metallicity properties between thoseof the old thin disk and the halo.
| New subdwarfs. V - Radial velocities for 889 high-proper-motion stars measured with the Mount Wilson 100 inch reflector
New radial velocities have been obtained from 2265 measurements of 889high-proper-motion stars taken from the subdwarf candidate list of aprevious paper. The observations were made with the Mount Wilson 100 inHooker reflector coude spectrograph with a Reticon detector, giving aninternal error of a single measurement of 4.7 km/s. From 88 stars incommon with previously known subdwarfs; the external error of the datais 6.9 km/s per measurement, and the velocity system is shown to be onthe system of the Wilson General Catalog to better than 1 km/s. Of the878 stars with nonvariable velocities in the sample, 38 have radialvelocities larger than 200 km/s, of which 22 are new. There is acorrelation between radial velocity and reduced ultraviolet excess asexpected from the previously known relations between space motion andchemical composition. The Stroemberg asymmetric drift is directlyvisible in the radial velocity and the proper-motion data separately aseach is displayed as a function of galactic longitude.
| New subdwarfs. IV - UBV photometry of 1690 high-proper-motion stars
A photometric list of 1690 stars of known high proper motion is used tosearch for potential high-velocity stars of various metallicity valuesin order to find candidates for trigonometric programs on subdwarfs andto enlarge the sample with which to study the relation between stellarkinematics and metal abundance. A list of 113 stars with tangentialspace velocities of 300 km/s or greater is obtained, the highesttangential velocity relative to the sun being 630 km/s. By using thevariation of the tangential velocity with longitude and adopting thegalactic rotation at the solar circle to be 220 km/s, the rotation ofthe subdwarf system is estimated at 0 + or - 50 km/s from the transversevelocity alone, in agreement with determinations based on other methods.
| G. P. Kuiper's spectral classifications of proper-motion stars
Spectral classifications are listed for over 3200 stars, mainly of largeproper motion, observed and classified by Kuiper during the years1937-1944 at the Yerkes and McDonald Observatories. While Kuiper himselfpublished many of his types, and while improved classifications are nowavailable for many of these stars, much of value remains. For many ofthe objects, no other spectral data exist.
| Lunar occultation summary. III
Observations of 242 photoelectric lunar occultation events studied atErwin W. Fick Observatory are reported. Approximately one-fourth ofthese are reappearances. From each observation are estimated the minimummagnitude differences between the observed object and possibleundetected companions. Occultation observations are given of 23 starsbrighter than 6th mag, including Alpha Vir, Beta-1 Sco, Mu Gem, Xi-2Sgr, Zeta Tau, Lambda Gem, and Beta Cap.
| Photographic measures of double stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978A&AS...31..121A&db_key=AST
| Lowell proper motions III : proper motion survey of the Northern Hemisphere with the 13-inch photographic telescope of the Lowell Observatory
Not Available
| The visual magnitudes of double stars.
Not Available
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תצפית ומידע אסטרומטרי
| קבוצת-כוכבים: | שור |
| התרוממות ימנית: | 05h33m06.93s |
| סירוב: | +20°02'08.1" |
| גודל גלוי: | 9.02 |
| מרחק: | 46.062 פארסק |
| תנועה נכונה: | -82 |
| תנועה נכונה: | -287.6 |
| B-T magnitude: | 10.045 |
| V-T magnitude: | 9.105 |
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