Sixth Catalogue of Fundamental Stars (FK6). Part III. Additional fundamental stars with direct solutions
The FK6 is a suitable combination of the results of the HIPPARCOSastrometry satellite with ground-based data, measured over a longinterval of time and summarized mainly in the FK5. Part III of the FK6(abbreviated FK6(III)) contains additional fundamental stars with directsolutions. Such direct solutions are appropriate for single stars or forobjects which can be treated like single stars. Part III of the FK6contains in total 3272 stars. Their ground-based data stem from thebright extension of the FK5 (735 stars), from the catalogue of remainingSup stars (RSup, 732 stars), and from the faint extension of the FK5(1805 stars). From the 3272 stars in Part III, we have selected 1928objects as "astrometrically excellent stars", since their instantaneousproper motions and their mean (time-averaged) ones do not differsignificantly. Hence most of the astrometrically excellent stars arewell-behaving "single-star candidates" with good astrometric data. Thesestars are most suited for high-precision astrometry. On the other hand,354 of the stars in Part III are Δμ binaries in the sense ofWielen et al. (1999). Many of them are newly discovered probablebinaries with no other hitherto known indication of binarity. The FK6gives, besides the classical "single-star mode" solutions (SI mode),other solutions which take into account the fact that hidden astrometricbinaries among "apparently single-stars" introduce sizable "cosmicerrors" into the quasi-instantaneously measured HIPPARCOS proper motionsand positions. The FK6 gives, in addition to the SI mode, the "long-termprediction (LTP) mode" and the "short-term prediction (STP) mode". TheseLTP and STP modes are on average the most precise solutions forapparently single stars, depending on the epoch difference with respectto the HIPPARCOS epoch of about 1991. The typical mean error of anFK6(III) proper motion in the single-star mode is 0.59 mas/year. This isa factor of 1.34 better than the typical HIPPARCOS errors for thesestars of 0.79 mas/year. In the long-term prediction mode, in whichcosmic errors are taken into account, the FK6(III) proper motions have atypical mean error of 0.93 mas/year, which is by a factor of about 2better than the corresponding error for the HIPPARCOS values of 1.83mas/year (cosmic errors included).
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1-m spectroscopy of normal OB stars
We have obtained spectra of 70 normal OB stars in the near-IR I(1-μm) band. The strongest features are those due to lines of thehydrogen Paschen series and neutral and ionized helium, which are, forthe most part, in absorption. The information content in this spectralrange is sufficient for only a rough classification of hot stars into`early O', `late O' and `B' types. Curiously, the leading He i tripletline, He i λ1.0830 μm, is usually not detectable, although ina few stars it is in emission; its behaviour generally correlates withthe leading helium singlet line, He i λ 2.058 μ m. These twofeatures appear to be present in emission only in stars with extremes ofmass loss or wind extension.
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Radio HI and optical absorption-line spectra of an intermediate-velocity cloud in the general direction of the M15 globular cluster
Using HI spectra obtained with the Lovell telescope (FWHM ~ 12 arcmin)we present maps showing the HI distribution and velocity structure of anintermediate-velocity cloud (IVC; v_LSR~70 km s^-1) which is observed inthe general direction of the globular cluster M15. The gas is shown tobe clumpy in nature and we examine its position and velocity structure.The IVC is detected in absorption in the CaII K line towards fivecluster stars in intermediate resolution spectra obtained with ISIS/WHTand in high resolution UES/WHT NaI D line spectra of two cluster stars(II-75; IV-38). The clumpy nature of the gas is indicated by the NaI andKI spectra obtained in the II-75 and IV-38 sightlines, which haveangular separation ~ 3.5 arcmin. The IVC is detected in KI in the highercolumn density II-75 sightline; this appears to be the first detectionof IVC or HVC gas in KI. The IVC gas towards M15 has a similar velocityto that observed towards HD 203664, some 3.1 deg away from the cluster.Similarities in the IVC gas velocity suggest a gas structure thatextends across both sightlines, although gas column densities areconsiderably higher towards M15. For a common feature, this would placethe M15 IVC at a height above the Galactic plane (z-distance) of<~1.5 kpc based on the Little et al. estimate of the HD 203664distance. From the fine-scale structure and column density observations,estimates are made of the space density of the small-scaleconcentrations. However, these remain uncertain and the presentobservations emphasize the need for higher spatial and spectralresolution studies to provide firmer estimates of cloud properties. Wereport also on a radio HI and CaII line survey towards a sample of 24stars over a wider field. This was carried out in an attempt to detectany wider distribution of the IVC gas and to place better limits on itsdistance. Although these observations are of sufficient spectralquality, no new optical detections are reported.
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H-Band Spectroscopic Classification of OB Stars
We present a new spectroscopic classification for OB stars based onH-band (1.5 \mic \ to 1.8 \mic) observations of a sample of stars withoptical spectral types. Our initial sample of nine stars demonstratesthat the combination of He 1 1.7002 \mic \ and H Brackett seriesabsorption can be used to determine spectral types for stars between ~O4 and B7 (to within ~ +/- 2 sub-types). We find that the Brackettseries exhibits luminosity effects similar to the Balmer series for theB stars. This classification scheme will be useful in studies ofoptically obscured high mass star forming regions. In addition, wepresent spectra for the OB stars near 1.1 \mic \ and 1.3 \mic \ whichmay be of use in analyzing their atmospheres and winds.
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A Spectral Atlas of Hot, Luminous Stars at 2 Microns
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996ApJS..107..281H&db_key=AST
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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.
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Optical and H I observations of high-velocity gas toward HD 203664
High-resolution optical stellar and interstellar observations toward thehalo star HD 203664 and six surrounding early-type stars have beencombined with a 21 cm mapping of the region to investigate a 70 kms-1 between 200 and 1500 pc; upper limits to temperature andvelocity dispersion of 4600 K and 2.2 km s-1 have beenestimated; and a column density ratio N(Na II)/N (Ca II) approx. equalto 0.32 has been deduced. These parameters are consistent with thematerial being shocked gas, possibly arising from an old supernovaremnant. The N(Na I)/N(H I) and N(Ca II)/N(H I) ratios are anomalouslylarge by factors of approximately 20 and 100, respectively, with respectto normal diffuse gas; several scenarios are presented as possibleexplanations of this phenomenon.
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K-Band Spectroscopy of OB Stars: A Preliminary Classification
Not Available
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Fifth fundamental catalogue. Part 2: The FK5 extension - new fundamental stars
The mean positions and proper motions for 3117 new fundamental starsessentially in the magnitude range about 4.5 to 9.5 are given in thisFK5 extension. Mean apparent visual magnitude is 7.2 and is on average2.5 magnitudes fainter then the basic FK5 which has a mean magnitude of4.7. (The basic FK5 gives the mean positions and proper motions for theclassical 1535 fundamental stars). The following are discussed: theobservational material, reduction of observations, star selection, andthe system for the FK5 extension. An explanation and description of thecatalog are given. The catalog of 3117 fundamental stars for the equinoxand epoch J2000.0 and B1950.0 is presented. The parallaxes and radialvelocities for 22 extension stars with large forecasting effects aregiven. Catalogs used in the compilation of the FK5 fundamental catalogare listed.
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Large and kinematically unbiased samples of G- and K-type stars. V - Evolved stars in the selected areas at + 15-deg declination
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1990PASP..102..242E&db_key=AST
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UBV photometry of stars whose positions are accurately known.
Photometric indices V, B-V, and U-B were measured for about 560 stars ofthe AGK3R and NPZT catalogs between BD declinations 11 deg and 23 deg,using the 40-cm Cassegrain telescope of the Kvistaberg Observatory fromApril 1986 to May 1987. The observation procedure and the reductiontechnique were the same as in the earlier papers of this series by Oja(1984, 1985, 1986, and 1987). The mean errors were calculated from theinternal consistency of the data. The accuracy was found to be the sameas for the earlier parts of the survey.
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Observations of interstellar diffuse absorption band at 4430 A
Observations of the interstellar diffuse absorption band at 4430 A for800 O and B stars in Neckel's (1967) catalog are being carried out, and482 spectra obtained up to September 1983 have been reduced. It isconfirmed that the strength of the interstellar diffuse absorption bandat 4430 A does not simply relate to the abundance of interstellar grainson the line of sight. The relation between the color excess E(B-V) andthe equivalent width of the band to the direction of l = 130-140 deg andb = -5 to +5 deg shows that some parameter(s) other than E(B-V) is (are)needed to understand the cause of this band.
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Catalog of O-B stars observed with Tokyo Meridian Circle
A catalog of the O-B stars, selected from 'Blaauw-Parenago' list andRubin's catalog, has been compiled on the FK4 system by the observationsmade with Gautier 8-inch Meridian Circle at the Tokyo AstronomicalObservatory during the period, 1971 to 1979. It contains 1059 stars andwas compiled for the future establishment of high precision propermotions of O-B stars.
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Spectral classification from the ultraviolet line features of S2/68 spectra. V - Supplement series
The paper presents the ultraviolet classification of more than 450 B-Aand F spectra obtained with the sky survey telescope mounted on the TD1satellite. Concerning abnormal objects, attention is given to the Bestars, the binary stars, the helium weak stars, and the lambda Booobjects. With regard to Be stars, it is concluded that the 1930 Awavelength feature is linked to the existence of either shell structuresor Fe II emission lines in the visual spectral range. In addition, it issuggested that stellar spectra at wavelengths of 1410, 1610-20 and 2400A are equivalent to the He-weak group in the classical range.
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Equivalent widths and rotational velocities of southern early-type stars
Not Available
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Observations of the 21-CM Hydrogen Line Toward High-Latitude Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1969ApJ...157.1101G&db_key=AST
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Troisième catalogue de l'Observatoire de Besançon comprenant 764 étoiles réduites à 1950, 0 sans mouvement propre et 326 étoiles FK3 pour l'époque moyenne d'observation
Not Available
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Photoelectric distances of 461 Northern OB-stars and galactic structure from Hγ- luminosities Author: Beer, A.
Abstract image available at:http://adsabs.harvard.edu/abs/1964MNRAS.128..261B
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Distances of southern B-stars and galactic structure from Hγ-luminosities
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1961MNRAS.123..191B&db_key=AST
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Proper motions of 650 bright B-type stars.
Not Available
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