Stars with ISM Polarization Observed with HPOL. II
Polarization data are given for stars whose polarizations are mostlyinterstellar which were observed with the University of Wisconsinspectropolarimeter (HPOL) during 1995-2003. Several cases are found forwhich K in the Serkowski Law for ISM polarization is higher than allowedby published formulas.
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Two-colour photometry for 9473 components of close Hipparcos double and multiple stars
Using observations obtained with the Tycho instrument of the ESAHipparcos satellite, a two-colour photometry is produced for componentsof more than 7 000 Hipparcos double and multiple stars with angularseparations 0.1 to 2.5 arcsec. We publish 9473 components of 5173systems with separations above 0.3 arcsec. The majority of them did nothave Tycho photometry in the Hipparcos catalogue. The magnitudes arederived in the Tycho B_T and V_T passbands, similar to the Johnsonpassbands. Photometrically resolved components of the binaries withstatistically significant trigonometric parallaxes can be put on an HRdiagram, the majority of them for the first time. Based on observationsmade with the ESA Hipparcos satellite.
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On the relation between diffuse interstellar bands and simple molecular species
We present observations of the major diffuse interstellar bands (DIBs)at 5780 and 5797 Ä as well as literature data and our ownobservations of the violet lines of CH and CH(+) , in the lines of sighttoward some 70 stars representing various degrees of the interstellarreddening. The correlations are shown and discussed in the context ofindicators such as far-UV extinction parameters and neutral molecularabundances. The results show that the DIBs in question (lambda lambda5797 and 5780) both probably form in diffuse cloud interiors, in arelated regime where CH and H_2 form. The ratio of the two DIBscorrelates with CH abundance, confirming that the lambda 5797 carrier isfavoured in enhanced molecular gas regions over the lambda 5780 carrier.The ratio of the two DIBs correlates poorly with CH(+) abundance. Ourcompilation of observational data also suggests that the DIB ratio maybe equally useful as a cloud type indicator as is R_V, the ratio oftotal to selective extinction, and much more readily observed. Based onobservations obtained at the Russian Special Astrophysical Observatory(SAO), Terskol Observatory (TER), Canada France Hawaii Telescope (CFHT),European Southern Observatory (ESO), Observatoire de Haute-Provence(OHP)
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Spectroscopic investigation of bright stars in the CEP OB2 association.
Not Available
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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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Atlas of extinction curves derived from ultraviolet spectra of the TD-1 satellite
The collection of 166 extinction curves derived from the publishedlow-resolution spectra acquired with the aid of the spectrometer onboard the TD-1 satellite is presented. The observed variety ofextinction laws is apparently due to the varied physical parameters ofinterstellar clouds; for example, the bright stars, included in thesample of TD-1 material, are very likely to be obscured by single clouds(interstellar or circumstellar). The system of standards constructedwith the aid of a special procedure allowing the possible effects ofspectral mismatch to be avoided and making possible the derivation ofextinction curves even in cases of very small E(B-V)S, was applied. Thecurves are presented in the form of plots, normalized to E(B-V) = 1.
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Absolute magnitudes of B emission line stars - Correlation between the luminosity excess and the effective temperature
A new determination of the visual absolute magnitude of Be stars iscarried out. For this, a new calibration of visual absolute magnitudesof B stars of luminosity classes, V, IV, and III is first obtained froma sample of 215 stars. The absolute luminosity excess in the visual isdetermined for a sample of 49 Be stars. It is found that this excess iscorrelated with the effective temperature of the underlying stars. Awell defined correlation between this excess and the emission in thefirst two Balmer lines is established. From these results, using asimple model of circumstellar envelope, it is inferred that the zones ofthe circumstellar envelope contributing to the emission in the continuumand in the lines have to be rather small. It is also deduced that theemission measure of the envelope is correlated with the temperature ofthe central star and that the irregular photometric variations of Bestars are an envelope-opacity phenomenon.
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Flamsteed stars not contained in the Yale "Catalogue of Bright Stars"
Not Available
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A study of the ultraviolet spectrum of VV Cephei
The IUE images of the atmospheric eclipsing binary VV Cep (M 2 Ia e + B,P = 20.3 yr) were studied. The absorption and emission lines in thehigh-resolution spectra were identified. No interstellar absorptionlines were detected despite the large degree of reddening. Thecomparison of the UV energy distribution of VV Cep after the end of theeclipse with several standard stars observed with IUE gives a spectraltype A0 II for the companion.
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The variation of interstellar extinction in the ultraviolet
One hundred and fifty-four reddened stars that are apparently normal inthe visible were selected from the S2/68 Ultraviolet Sky Survey. Theultraviolet data for 92 of these cannot be explained in terms of a fixedinterstellar extinction law. Between 1400 and 2740 A, the extinctioncurve for each star can be well represented by two parts; astraight-line scattering component and a Lorentzian 2200 A absorptionfeature. Independent variations are found in both parts and these cannotbe explained by photometric or spectral classification errors. Bothparts vary smoothly, implying that there is no fixed extinction law, andone star in three is found to depart from the mean law by more than 1mag at either 1500 or 2200 A. The two variations allow not only all 154stars to be explained but also anomalous stars reported by otherauthors. These are not special but merely situated towards the limits ofthe variations. A variation in the relative proportions of graphite andsilicate grains goes some way towards explaining the observations. Theprofile of the 2200 A feature is determined, the symmetrical shape isconfirmed, and the profile fits a Lorentzian very closely.
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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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On interstellar Fe X forbidden line absorption toward Cepheus OB2
A weak interstellar absorption line which can be identified as theforbidden line of Fe X 6375 A is observed in the spectrum of the A2 Iastar Nu Cep, which is a member of the Cepheus OB2 association. Theequivalent width, width, and radial velocity of the line differindistinguishably from those of similar absorption previously detecteduniquely toward the O6f star Lambda Cep, another association memberlocated at a projected distance of about 50 pc from Nu Cep. Theabsorption may reveal a particularly dense, low-latitude concentrationof hot, foreground interstellar gas of the kind generally responsiblefor the observed soft X-ray background.
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Spectrophotometric investigation of OB stars in the region of the association CEP OB2
The results are given of spectrophotometric investigation of 39 OB starsin the region of the association Cep OB2. The blue (4000-4800 A)absolute spectrophotometric gradients, the color excesses in the UBVsystem, and the distances of these stars have been determined. Analysisof the results suggests that the absorbing material is basicallyconcentrated within the association itself.
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Confirmation among visual multiples of an increase of AP stars with age
Open clusters with ages below certain threshold values contain no Apstars and those with greater ages contain numbers of Ap stars thatapparently increase with age. But in view of the few young clustersstudied, the data could also be interpreted in terms of randomdifferences in the frequencies of Ap stars between individual clusters,rather than an age effect. Data on 77 field visual multiple systems(that originated from many different clusters and associations) in whichthe primaries are O5-A1 stars and the secondaries occur in the absolutemagnitude range of the Ap stars were, therefore, obtained. Againspectral classification shows no Ap stars in systems with ages notgreater than 1,000,000 yr and a steady increase in Ap stars thereafter.The numerical agreement with the cluster data is good, confirming thatthe cluster data are exhibiting a real age effect.
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The interstellar 2200 A band - A catalogue of equivalent widths
Not Available
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Photoelectric photometry of luminous B-type stars in a Milky Way field in Cepheus
Not Available
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On the relationship between the apparent magnitudes given in several catalogues and the UBV system.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974A&AS...15..215O&db_key=AST
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La classification stellaire BCD : parametre caracteristique DU type spectral calibration EN magnitudes absolues.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973A&A....23...69C&db_key=AST
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A Spectroscopic and Photometric Investigation of the Association Cepheus OB2
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1968ApJ...154..923S&db_key=AST
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Spiral arms
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1967MNRAS.137..337D&db_key=AST
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Catalogue d'etoiles O et B.
Not Available
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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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Luminosities and photometric distances of early-type stars
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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Seven-Colour Photometry of O, B and A Stars.
Not Available
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Proper motions of 650 bright B-type stars.
Not Available
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Studies in Galactic Structure. I. a Preliminary Determination of the Space Distribution of the Blue Giants.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1953ApJ...118..318M&db_key=AST
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Intensities of the Interstellar Band at λ 4430.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1951ApJ...113..100D&db_key=AST
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On the cause underlying the spectral differences of the stars.
Not Available
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INHABITED SKY
