Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics
The Catalogue, available at the Centre de Données Stellaires deStrasbourg, consists of 13 573 records concerning the results obtainedfrom different methods for 7778 stars, reported in the literature. Thefollowing data are listed for each star: identifications, apparentmagnitude, spectral type, apparent diameter in arcsec, absolute radiusin solar units, method of determination, reference, remarks. Commentsand statistics obtained from CADARS are given. The Catalogue isavailable in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcar?J/A+A/367/521
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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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Spectral synthesis in the ultraviolet. IV - A library of mean stellar groups
A library of mean UV stellar energy distributions is derived from IUEspectrophotometry of 218 stars. The spectra cover 1230-3200 A with aspectral resolution of about 6 A. They have been corrected forinterstellar extinction and converted to a common flux and wavelengthscale. Individual stars were combined into standard groups according totheir continuum colors, observed UV spectral morphology, MK luminosityclass, and metal abundance. The library consists of 56 groups: 21dwarf(V), 8 subgiant(IV), 16 giant(III), and supergiant(I + II) groups,covering O3-M4 spectral types. A metal-poor sequence is included,containing four dwarf and two giant groups, as is a metal-enhancedsequence with a single dwarf, subgiant, and giant group. Spectralindices characterizing the continuum and several strong absorptionfeatures are examined as temperature, luminosity, and abundancediagnostics. The library is intended to serve as a basis forinterpreting the composite UV spectra of a wide variety of stellarsystems, e.g., elliptical galaxies, starburst systems, and high-redshiftgalaxies.
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A homogeneous catalog of new UBV and H-beta photometry of B- and A-type stars in and around the Scorpius-Centaurus OB association
B- and A-type stars in and near the Sco-Cen OB association areinvestigated with UBV and H-beta photometry to acquire data relevant tothe luminosity function of Sco-Cen. The measurements generally consistof two 10-s integrations of U, B, V, (W, N) filters, and theobservations are corrected iteratively for atmospheric extinction andinstrumental response. The data presented give the mean V magnitude,mean B-V, mean U-B, and the estimated uncertainties for these values.The catalog provides a homogeneous catalog of data for a large fieldwith stellar objects delineating membership to the association Sco-Cenand that affect the luminosity function of the aggregate.
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Observations that link infrared cirrus and ultraviolet extinction
Results are presented of UV extinction measurements of 17 stars in theopen cluster IC 4665 and of four stars in the open cluster NGC 1647,showing that the UV extinctions of the two clusters stars have differentproperties. Whereas the stars in NGC 1647 cluster are typical of generalinterstellar space, the stars in IC 4665 have a small 'linear' termwhich is typical of stars found near regions of active star formation.Using data from the IRAS satellite to study the emission by the'infrared cirrus' for each of the regions and to measure theI(60-micron)/I(100-micron) ratio for the two regions, it was found that,when the linear term component is present, it dominates the 100-microncirrus emission. When it is absent, the 100-micron emission is from therelatively hot particles that are responsible for the 60-micronemission. It is suggested that the 60-micron emitters are smallcarbonaceous grains that are major contributors to all parts of the UVextinction except the linear term.
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Spectral synthesis in the ultraviolet. III - The spectral morphology of normal stars in the mid-ultraviolet
The morphology of 218 mid-UV spectra of stars ranging from O through Kin spectral type is examined. Several new line and continuum indices aredefined and their usefulness as temperature, luminosity, and metallicitydiscriminants is discussed. Mid-UV stellar continua are found to bemarkedly affected by abundance. A UV excess, delta(2600-V), is computedwhich is more sensitive by a factor of 10 to (Fe/H) than is delta(U-B).The relative strength of spectral lines in the mid-UV is not as stronglyaffected by abundance. Mid-UV spectra are much more sensitive to thetemperature of the stellar population than to either metallicity or thedwarf/giant ratio. Mg II 2800 shows unexpected behavior, displaying nosensitivity to abundance for cool stars and a reversed sensitivity in FGdwarfs such that metal-poor stars have stronger Mg II strengths at thesame temperature than more metal-rich stars.
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The early A type stars - Refined MK classification, confrontation with Stroemgren photometry, and the effects of rotation
The MK classification system for the early A-type stars is refined, anda parallel system of standards for the broad-lined stars is introduced.With this improved system, stars may be classified with significantlygreater precision than before. It is shown that spectral types in thissystem are not systematically affected by rotational line broadening. Atotal of 372 early A-type stars are classified, and a confrontation ofthese spectral types with Stroemgren photometry reveals a number ofsystematic photometric effects of rotation. In particular, high v sin istars are systematically redder than low v sin i stars of the samespectral type, and the beta index is weakened by rotation. It isconcluded that precise spectral classification in conjunction withStroemgren and H-beta photometry can potentially provide a valuablecheck and input to the theory of the atmospheres of rotating stars.
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The moderately interacting Algol-type eclipsing binary RY Geminorum
Ultraviolet spectra of the Algol-type semidetached system RY Geminorum,whose components can be described as A0 V and K0 IV, have been matchedto the ultraviolet spectrum by Kurucz (1979) model atmospheres, and abest fit is found for T(eff) = 9150 K. Comparison with standard starspectra requires that this value be raised to 9400 K. The color excessof the system is determined to be no more than E(B-V) = 0.03 mag; thedistance to the system is about 360 pc. The masses are approximately2.36 and 0.38 solar masses, and the radii are 2.5 and 5.8 solar radii,respectively. The separation of the two centers is 26 solar radii.Evidence for a circumstellar line absorption is found in optical andultraviolet spectrograms, and evidence is found in IUE spectra taken inpartial eclipse for circumstellar emission lines of the type detectedpreviously in the WS Serpentis stars and in several semidetected systemsof the Algol type.
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Intensities of the resonance lines of neutral and ionized magnesium in stellar spectra
Empirical curves giving the dependence of the equivalent widths of thedoublet 2800 Mg II and the line 2852 Mg I on the spectral class havebeen plotted. Some features of the behavior of these lines in thespectra of stars of the spectral classes A-K have been analyzed. Thelines 2795 Mg II and 2852 Mg I have been used to determine the meanelectron concentration ne(Mg) in the atmospheres of 87 stars of thespectral classes B8-K4.
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IUE low-dispersion reference atlas
This atlas, published by ESA and essentially devoted to normal stars,presents 229 graphic spectra together with the corresponding fluxes andan ultraviolet spectral type. The preparation of this publicationconfirmed that MK classifications cannot simply be transferred to theultraviolet range. A set of transparencies illustrates the referencesequences constructed from the ultraviolet data. A magnetic-tape copy ofall the spectra pertaining to this atlas is available from the StellarData Center in Strasbourg.
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A Note about the Comparison Between the Old and New Slettebak Systems of Axial Rotational Velocities
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1984RMxAA...9....9G&db_key=AST
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IUE low-dispersion spectra flux catalogue. I - Normal stars (magnetic tape)
A magnetic tape catalog of the fluxes (2A-step) of 229 selectedlow-dispersion stellar spectra prepared by the Centre de Calcul deStrasbourg-Cronenbourg is presented in the form of a set of tables. Thecatalog uses the general MK frame and centers on stars exhibiting normalbehavior in the ultraviolet. All the stars included in the catalog arelisted together with their MK and UV spectral classifications. Thespectra were collected by the International Ultraviolet Explorer (IUE)with the aim of establishing reference spectral sequences in theultraviolet range.
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Correlations between the lambda 2200 feature, the diffuse lambda 4430 band, and E/B-V/
The 2200 A extinction feature has been measured from ANS observations of30 stars. For each star, the depth of the 2200 A feature is compared toE(B-V) and the equivalent width of the diffuse band 4430 A. A goodcorrelation appears out to E(B-V) = 1.13. The various mechanisms forproducing the diffuse and 2200 A features are discussed and adiscriminatory test is put forward based on observations of theMagellanic Clouds.
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Prediction of spectral classification from photometric observations - Application of the UVBY beta photometry and the MK spectra classification. II - General case
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1980A&A....85...93M&db_key=AST
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Prediction of spectral classification from photometric observations-application to the UVBY beta photometry and the MK spectral classification. I - Prediction assuming a luminosity class
An algorithm based on multiple stepwise and isotonic regressions isdeveloped for the prediction of spectral classification from photometricdata. The prediction assumes a luminosity class with reference touvbybeta photometry and the MK spectral classification. The precisionattained is about 90 percent and 80 percent probability of being withinone spectral subtype respectively for luminosity groups I and V and forluminosity groups III and IV. A list of stars for which discrepanciesappear between photometry and spectral classification is given.
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Five-channel photometry of cepheids and supergiants in the southern Milky Way.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976A&AS...24..413P&db_key=AST
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Observations of the diffuse 4430 A absorption band in southern O, B, and A stars
Photoelectric narrow-band observations of the intensity of the diffuseinterstellar 4430 A absorption band have been carried out for 65southern O, B and A stars of luminosity classes I and II. The dependenceof the 4430 A index on stellar spectral lines is eliminated and thevariation of the ratio Jc/E(B-V) of 4430-A wavelength to selectiveabsorption from place to place in the Galaxy is discussed. It is foundthat Jc/E(B-V) is significantly lower in the inter-arm region frominside the inner and outer spiral arms. The observed value of Jc/E(B-V)for HD 153919, the optical component of the binary system containing theX-ray source 2 U 1700-37, indicates a distance of at least 1.5 kpc whichsuggests that it is more luminous and massive than an ordinary O 6 star.
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Rotational Velocities and Spectral Types of Some A-Type Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972PASP...84..584L&db_key=AST
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Four-colour and H BET photometry of some bright southern stars- II.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972MNRAS.160..155S&db_key=AST
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Fundamental data for southern stars (Second List)
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1959MNRAS.119..638E&db_key=AST
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INHABITED SKY
