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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.
| Overionization of neutral iron in the atmospheres of solar-type subdwarfs
The model atmosphere method is used to perform iron abundancecomputations for 30 subdwarfs with T(eff) between 5500 and 6500 K in theFe/H range between -0.1 and -2.3. It is shown that there is a systematicdifference in the iron abundances determined from Fe I and Fe II lines.This difference increases with decreasing metallicity. Non-LTEcomputations of the Fe I-Fe II ionization balance are performed usingobserved UV fluxes. It is found that, in the atmospheres of subdwarfs,an overionization of neutral iron atoms occurs, leading to a weakeningof Fe I line intensity and to the systematic underestimation of theabundances. It is concluded that the Fe II lines must be used forcorrect determinations of iron abundance in the atmospheres of subdwarfssince they are not sensitive to the effect of the overionization of FeI.
| U, V, W velocity components for the old disk using radial velocities of 1295 stars in the three cardinal Galactic directions
New radial velocities are presented for 1295 stars chosen at random nearthe three cardinal Galactic directions of l = 180 deg, b = 0; l = 90deg, b = 0 deg; and b = 90 deg, giving the distribution in U, V, and W,respectively, from the radial velocities alone. The measurements weremade with the coude spectrograph of the Mount Wilson 100 in. Hookerreflector. The purpose of the program is to set limits on the densitynormalization in the solar neighborhood of the old thin disk, the oldthick disk, and the halo. Many more high-velocity stars are present inthe unbiased sample than expected from previous estimates of thenormalization. The data suggest the density ratios in the solarneighborhood to be about 90 percent, 10 percent, and about 0.5 percentfor the thin disk, thick disk, and halo populations, respectively.
| A photometric search for halo binaries. I - New observatinal data. II - Results
Carney (1982) has reported JHK photometry for 76 Hyades dwarfs. Inconnection with the present investigation, results of similarobservations of field halo stars are provided along with some uvbyphotometry. In addition, older spectrophotometric and photometric dataused previously for temperature determinations have been collected. Theinfrared and uvby data were obtained primarily with the objective ofidentifying binaries with dissimilar components among a sample of fieldhalo dwarfs by comparing metallicity insensitive blue and infraredcolors. Attention is given to 111 spectrophotometric scans of 89 stars,67 uvby measures of 41 stars, 127 UBV measures of 87 stars, 147 (RI)Jmeasures of 127 stars, 8 JHK measures of eight stars in the 'HCO'system, and 212 JHK measures of 137 stars in the 'CIT' system. Themajority of these stars are dwarfs, and most of them are metal poor. Theresults of a search for binaries in 71 halo dwarf stars are alsopresented, taking into account a few other dwarfs of special interest.
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| Takýmyýldýz: | Arabaci |
| Sað Açýklýk: | 05h41m56.64s |
| Yükselim: | +29°16'05.2" |
| Görünürdeki Parlaklýk: | 8.511 |
| özdevim Sað Açýklýk: | -2 |
| özdevim Yükselim: | 22.4 |
| B-T magnitude: | 9.134 |
| V-T magnitude: | 8.563 |
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