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Kinematics of RHB stars to trace the structure of the Galaxy
Red horizontal-branch (RHB) stars have been selected from the Hipparcoscatalogue to investigate their kinematics and spatial distribution.Hipparcos parallaxes, literature radial velocities and Hipparcos propermotions, together with models for the gravitational potential of theMilky Way allow a calculation of the actual velocity vectors and theorbits of the RHB stars. The velocity characteristics are used to definea halo population sample (HPS) in the collection of RHBs. The orbitslead statistically to an overall z-distance probability distribution,showing that the RHBs exhibit two populations, a disk one having a scaleheight of hdisk ≃ 0.6 kpc and a halo one of ≃4kpc. We have investigated the influence on our results of parallaxaccuracy and of a demarcation line in the HRD between the RHB and thered-giant (RG) star region. Neither of them show marked effects. We haveperformed the orbit analysis using the potential model of Allen &Santillan as well as of Dehnen & Binney. The results differ onlyslightly for the disk population, showing that these potential modelsare not a critical part of such orbit investigations. RHB scale heightvalues are smaller than those found earlier for sdB stars, most likelybecause the samples of stars used had different spatial distributions apriori. The data do not allow us to specify a trend in the kinematicbehaviour of star types along the horizontal branch.
| 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.
| A. de Sitter's photographic polar photometry revisited; some remarks on photographic photometry with objective gratings
Not Available
| Narrow-band photometry of late-type stars. II
This paper presents extensive narrow-band photometry in the Uppsalasystem supplementing earlier published mesurements so that data now areavailable for all late-type stars brighter than V = 6.05 and a number ofgalactic cluster members. Numerous UBV and BV measurements are alsopublished. The data are used to determine relations for the predictionof UBV intrinsic colors for late-type stars from the narrow-bandmeasurements. The main purpose of the data is to constitute the basisfor the determination of solar-neighborhood space densities of late-typestars, mainly giants of different kinds; these space densities will becombined with narrow-band data for fainter stars in the north Galacticpole region to yield the decrease of space density with distance fromthe galactic plane for many kinds of late-type stars.
| Photographic magnitudes of stars brighter than 7m.75 between +75° and +80° declination (Errata: 11 270)
Not Available
| Yerkes actinometry. Zone +73deg to +90deg.
Not Available
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Osservazione e dati astrometrici
| Costellazione: | Cefeo |
| Ascensione retta: | 21h24m49.70s |
| Declinazione: | +80°31'29.0" |
| Magnitudine apparente: | 5.97 |
| Distanza: | 108.932 parsec |
| Moto proprio RA: | 41.8 |
| Moto proprio Dec: | -9.9 |
| B-T magnitude: | 7.159 |
| V-T magnitude: | 6.07 |
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