Early-type stars observed in the ESO UVES Paranal Observatory Project - I. Interstellar NaI UV, TiII and CaII K observations*
We present an analysis of interstellar NaI (λair=3302.37 and 3302.98 Å), TiII(λair= 3383.76Å) and CaII K (λair= 3933.66 Å) absorptionfeatures for 74 sightlines towards O- and B-type stars in the Galacticdisc. The data were obtained from the Ultraviolet and Visual EchelleSpectrograph Paranal Observatory Project, at a spectral resolution of3.75 km s-1 and with mean signal-to-noise ratios per pixel of260, 300 and 430 for the NaI, TiII and CaII observations, respectively.Interstellar features were detected in all but one of the TiIIsightlines and all of the CaII sightlines. The dependence of the columndensity of these three species with distance, height relative to theGalactic plane, HI column density, reddening and depletion relative tothe solar abundance has been investigated. We also examine the accuracyof using the NaI column density as an indicator of that for HI. Ingeneral, we find similar strong correlations for both Ti and Ca, andweaker correlations for Na. Our results confirm the general belief thatTi and Ca occur in the same regions of the interstellar medium (ISM) andalso that the TiII/CaII ratio is constant over all parameters. We henceconclude that the absorption properties of Ti and Ca are essentiallyconstant under the general ISM conditions of the Galactic disc.
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A high-resolution spectroscopy survey of β Cephei pulsations in bright stars
We present a study of absorption line-profile variations in early-B typenear-main-sequence stars without emission lines. We have surveyed atotal of 171 bright stars using the Nordic Optical Telescope (NOTSA),William Herschel Telescope (ING) and Coudé Auxiliary Telescope(ESO). Our sample contains 75% of all O9.5-B2.5 III-V non-emission-linestars brighter than 5.5 mag. We obtained high signal-to-noise,high-resolution spectra of the SiIII λ4560 triplet - for 125stars of our sample we obtained more than one spectrum - and examinedthese for pulsational-like line-profile variations and/or structure. Weconclude that about half of our sample stars show evidence forline-profile variations (LPV). We find evidence for LPV in about 65% ofour sample stars brighter than V=5.5. For stars with rotationalbroadening V sin i 100 km s-1, we find evidence for LPVin about 75% of the cases. We argue that it is likely that these LPV areof pulsational origin, and that hence more than half of thesolar-neighbourhood O9.5-B2.5 III-V stars is pulsating in modes that canbe detected with high-resolution spectroscopy. We detected LPV in 64stars previously unknown to be pulsators, and label these stars as newβ Cep candidates. We conclude that there is no obvious differencein incidence of (pulsational) LPV for early-B type near-main-sequencestars in binaries or in OB associations, with respect to single fieldstars.
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The Identification of New Be Stars in GAUDI
The Ground-based Asteroseismology Uniform Database Interface (GAUDI) isthe result of the preparatory work performed for the COROT satellite. Inthe data available in GAUDI we discovered 17 B-type stars that showemission in their Balmer lines and were not known to display suchemission before, including at least 16 nonsupergiant ones. We thusreclassify those stars as Be stars. These 17 new Be stars increase thenumber of Be stars in the field of view of COROT by ~25%, which isimportant for the target selection of the mission. Moreover, ~70% of thediscovered Be stars are of late subtypes. Be stars have been mostlyfound among early subtypes until now, but this could be due to anobservational bias. Finally, one of the discovered stars is either aslowly rotating shell Be star or a Herbig Be star with a low vsini,which makes this star especially interesting.Based on GAUDI, the data archive and access system of the ground-basedasteroseismology programme of the COROT mission. The GAUDI system ismaintained at LAEFF (http://ines.laeff.esa.es/corot/). LAEFF is part ofthe Space Science Division of INTA.
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Radial velocities. Measurements of 2800 B2-F5 stars for HIPPARCOS
Radial velocities have been determined for a sample of 2930 B2-F5 stars,95% observed by the Hipparcos satellite in the north hemisphere and 80%without reliable radial velocity up to now. Observations were obtainedat the Observatoire de Haute Provence with a dispersion of 80Ä,mm(-1) with the aim of studying stellar and galactic dynamics.Radial velocities have been measured by correlation with templates ofthe same spectral class. The mean obtained precision is 3.0 km s(-1)with three observations. A new MK spectral classification is estimatedfor all stars. Based on observations made at the Haute ProvenceObservatory, France and on data from The Hipparcos Catalogue, ESA.Tables 4, 5 and 6 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr or viahttp://cdsweb.u-strasbg.fr/Abstract.htm
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Photoelectric Photometry of Stars in the Orion Standard Region
Magnitudes and color indices in the Vilnius seven-color photometricsystem are given for 108 stars in the Orion standard region around theOrion Belt and the star lambda Orionis. New spectral and luminosityclasses, estimated from the photometric data, are given for some of thestars.
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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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An IUE survey of interstellar H I LY alpha absorption. 1: Column densities
We measure Galactic interstellar neutral hydrogen column densities byanalyzing archival interstellar Ly alpha absorption line data toward 554B2 and hotter stars observed at high resolution with the IUE satellite.This study more than doubles the number of lines of sight with measuresof N(H I) based on Ly alpha. We have included the scattered lightbackground correction algorithm of Bianchi and Bohlin in our datareduction. We use the correlation between the Balmer discontinuity(c1) index and the stellar Ly alpha absorption in order toassess the effects of stellar Ly alpha contamination. Approximately 40%of the B stars with measured (c1) index, exhibit seriousstellar Ly alpha contamination. One table contains the derived values ofthe interstellar N(H I) for 393 stars with at most small amounts ofstellar contamination. Another lists the observed values of total N(H I)for 161 stars with suspected stellar Ly alpha contamination and/oruncertain stellar parameters.
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Far-ultraviolet stellar photometry: A field in Orion
Far-ultraviolet photometry for 625 objects in Orion is presented. Thesedata were extracted from electrographic camera images obtained duringsounding rocket flights in 1975 and 1982. The 1975 images were centeredclose to the belt of Orion while the 1982 images were centeredapproximately 9 deg further north. One hundred and fifty stars fell inthe overlapping region and were observed with both cameras. Sixty-eightpercent of the objects were tentatively identified with known starsusing the SIMBAD database while another 24% are blends of objects tooclose together to separate with our resolution. As in previous studies,the majority of the identified ultraviolet sources are early-type stars.However, there are a significant number for which no such identificationwas possible, and we suggest that these are interesting objects whichshould be further investigated. Seven stars were found which were brightin the ultraviolet but faint in the visible. We suggest that some ofthese are nearby white dwarfs.
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Galactic interstellar abundance surveys with IUE. II - The equivalent widths and column densities
This paper continues a survey of interstellar densities, abundances, andcloud structure in the Galaxy, using the International UltravioletExplorer (IUE) satellite. Equivalent widths of 18 ultraviolet resonancetransitions are presented and column densities for Si II, Mn II, Fe II,S II, and Zn II toward 261 early-type stars are derived. Theseequivalent widths and column densities agree within the stated errors ofearlier Copernicus, BUSS, or IUE surveys of Mn II, Fe II, S II, and ZnII for 45 stars in common. The column densities are derived fromsingle-component curves of growth with a common b-value based on that ofFe II and Si II.
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IUE-IRAS studies of the infrared cirrus
The 60 and 100 micron cirrus emission around 256 lines of sight in theIRAS all-sky survey was measured, and the flux averages were used tostudy the distribution, variations, and correlations of the IRASinfrared cirrus fluxes with various interstellar parameters. It wasfound that the 60 and 100 micron fluxes correlate with the depletion ofSi and show a trend with the depletion of Fe for 51 lines of sighttoward the Galactic halo. No correlation was found with the abundancesof Si, Mn, Fe, S, or Zn or with abundance ratios for the full sample of256 stars. An abundance ratio of about 3 x 10 to the 7th by numberrelative to H was derived from 60 and 100 micron flux ratios and the Hcolumn along the line of sight; this ratio appears to decrease by afactor of 10 into the halo.
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Galactic interstellar abundance surveys with IUE. III - Silicon, manganese, iron, sulfur, and zinc
This paper continues a survey of intestellar densities, abundances, andcloud structure in the Galaxy using the IUE satellite. A statisticaldata set of 223 O3-B2.5 stars is constructed, including 53 stars in theGalactic halo. It is found that S II lines in B stars, of luminosityclasses IV and V, have possible contamination from stellar S II,particular for stars with v sin i less than 200 km/s. The meanlogarithmic depletions are -1.00, -1.19. -0.63, and -0.23 (Si, Mn,Fe,S,Zn). Depletions of Si, Mn, and Fe correlate with the mean hydrogendensity n-bar along the line of sight, with a turnover for n-bar greaterthan 1/cm. Sulfur depletions correlate with n-bar along the line ofsight. The slight Zn depletion correlation also appears to bestatistically insignificant. No correlation of depletion is found withthe physical density derived from H2 rotational states in 21 lines ofsight. Depletion variations in the disk are consistent with a Galacticabundance gradient or with enhanced mean depletions in the anticenterregion.
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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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Galactic interstellar abundance surveys with IUE. I - Neutral hydrogen
A survey is initiated of interstellar densities, abundances, and cloudstructure in the Galaxy, using the International Ultraviolet Explorer.From high-resolution (0.1-A) spectra, interstellar column densities arederived toward 244 early-type stars by fitting the damping wings of theLy-alpha absorption line. Published B-V photometry is used to deriveE(B-V) color excesses, stellar distances r, and the mean hydrogendensities, n-bar = N(H I)/r. The data set includes stars out to r = 8.5kpc and E(B-V) = 0.86, with 68 stars in the galactic halo (absolute bgreater than 20 deg). The statistical sample consists of 205 stars oftype O3-B2.5 within 5 kpc (53 stars in the halo). The column densities,log N(H I), range from less than 19.44 per square centimeter for alphaVir to 21.81 for HD 37061. A statistical analysis of the E(B-V)distribution suggests variations in the line-of-sight cloud density andthe mean reddening per cloud.
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Meridian observations made with the Carlsberg Automatic Meridian Circle at Brorfelde (Copenhagen University Observatory) 1981-1982
The 7-inch transit circle instrument with which the present position andmagnitude catalog for 1577 stars with visual magnitudes greater than11.0 was obtained had been equipped with a photoelectric moving slitmicrometer and a minicomputer to control the entire observationalprocess. Positions are reduced relative to the FK4 system for each nightover the whole meridian rather than the usual narrow zones. Thepositions of the FK4 stars used in the least squares solution are alsogiven in the catalog.
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H-beta photometry of northern intermediate galactic latitude early-type stars and galactic structure away from the plane
Photoelectric H-beta photometry is presented for 255 early-type stars atintermediate galactic latitudes. Absolute magnitudes and distances arederived for the more luminous stars. Those with visual magnitudes lessthan or equal to 2.5 and at distances of up to 1 kpc from the galacticplane may follow the spiral structure in the plane.
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UBV photometry and MK spectral classification of northern early-type stars at intermediate galactic latitudes
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977MNRAS.180..691H&db_key=AST
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Equivalent widths and rotational velocities of southern early-type stars
Not Available
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UBV photometry of 180 early-type stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974PASP...86..795G&db_key=AST
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Some Spectroscopic Characteristics of the OB Stars: an Investigation of the Space Distribution of Certain OB Stars and the Reference Frame of the Classification
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971ApJS...23..257W&db_key=AST
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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 measures of the 4430 A diffuse interstellar band
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1963MNRAS.125..141W&db_key=AST
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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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INHABITED SKY
