A Search for High-Velocity Be Stars
We present an analysis of the kinematics of Be stars based uponHipparcos proper motions and published radial velocities. We findapproximately 23 of the 344 stars in our sample have peculiar spacemotions greater than 40 km s-1 and up to 102 kms-1. We argue that these high-velocity stars are the resultof either a supernova that disrupted a binary or ejection by closeencounters of binaries in young clusters. Be stars spun up by binarymass transfer will appear as high-velocity objects if there wassignificant mass loss during the supernova explosion of the initiallymore massive star, but the generally moderate peculiar velocities of BeX-ray binaries indicate that the progenitors lose most of their massprior to the supernova (in accordance with model predictions). Binaryformation models for Be stars predict that most systems bypass thesupernova stage (and do not receive runaway velocities) to createultimately Be+white dwarf binaries. The fraction of Be stars spun up bybinary mass transfer remains unknown, since the post-mass transfercompanions are difficult to detect.
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A representative sample of Be stars III: H band spectroscopy
We present H band (1.53 mu m-1.69 mu m) spectra of 57 isolated Be starsof spectral types O9-B9 and luminosity classes III, IV & V. The H iBrackett (n-4) series is seen in emission from Br-11-18, and Fe iiemission is also apparent for a subset of those stars with H i emission.No emission from species with a higher excitation temperature, such asHe ii or C iii is seen, and no forbidden line emission is present. Asubset of 12 stars show no evidence for emission from any species; thesestars appear indistinguishable from normal B stars of a comparablespectral type. In general the line ratios constructed from thetransitions in the range Br-11-18 do not fit case B recombination theoryparticularly well. Strong correlations between the line ratios withBr-gamma and spectral type are found. These results most likelyrepresent systematic variations in the temperature and ionization of thecircumstellar disc with spectral type. Weak correlations between theline widths and projected rotational velocity of the stars are observed;however no systematic trend for increasing line width through theBrackett series is observed.
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A representative sample of Be stars. IV. Infrared photometry and the continuum excess
We present infra-red (JHK) photometry of 52 isolated Be\ stars ofspectral types O9-B9 and luminosity classes III-V. We describe a newmethod of reduction, enabling separation of interstellar reddening andcircumstellar excess. Using this technique we find that the discemission makes a maximum contribution to the optical (B-V) colour of afew tenths of a magnitude. We find strong correlations between a rangeof emission lines (Hα , Brgamma , Br11, and Br18) from the Bestars' discs, and the circumstellar continuum excesses. We also findthat stellar rotation and disc excess are correlated.
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Statistical analysis of intrinsic polarization, IR excess and projected rotational velocity distributions of classical Be stars
We present the results of statistical analyses of a sample of 627 Bestars. The parameters of intrinsic polarization (p*),projected rotational velocity (v sin i), and near IR excesses have beeninvestigated. The values of p* have been estimated for a muchlarger and more representative sample of Be stars (~490 objects) thanpreviously. We have confirmed that most Be stars of early spectral typehave statistically larger values of polarization and IR excesses incomparison with the late spectral type stars. It is found that thedistributions of p* diverge considerably for the differentspectral subgroups. In contrast to late spectral types (B5-B9.5), thedistribution of p* for B0-B2 stars does not peak at the valuep*=0%. Statistically significant differences in the meanprojected rotational velocities (/line{vsin i}) are found for differentspectral subgroups of Be stars in the sense that late spectral typestars (V luminosity class) generally rotate faster than early types, inagreement with previously published results. This behaviour is, however,not obvious for the III-IV luminosity class stars. Nevertheless, thecalculated values of the ratio vt/vc of the truerotational velocity, vt, to the critical velocity forbreak-up, vc, is larger for late spectral type stars of allluminosity classes. Thus, late spectral type stars appear to rotatecloser to their break-up rotational velocity. The distribution of nearIR excesses for early spectral subgroups is bi-modal, the position ofthe second peak displaying a maximum value E(V-L)~ 1 . m 3for O-B1.5 stars, decreasing to E(V-L)~0. m8 for intermediatespectral types (B3-B5). It is shown that bi-modality disappears for latespectral types (B6-B9.5). No correlations were found betweenp* and near IR excesses and between E(V-L) and vsin i for thedifferent subgroups of Be stars. In contrast to near IR excesses, arelation between p* and far IR excesses at 12 mu m is clearlyseen. A clear relation between p* and vsin i (as well asbetween p* and /line{vsin i}/vc) is found by thefact that plots of these parameters are bounded by a ``triangular"distribution of p*: vsin i, with a decrease of p*towards very small and very large vsin i (and /line{vsini}/vc) values. The latter behaviour can be understood in thecontext of a larger oblateness of circumstellar disks for the stars witha rapid rotation. From the analysis of correlations between differentobservational parameters we conclude that circumstellar envelopes forthe majority of Be stars are optically thin disks with the range of thehalf-opening angle of 10degr
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A representative sample of Be stars. II. K band spectroscopy
We present K band (2.05 mu m - 2.22 mu m) spectra of 66 isolated Bestars of spectral types O9-B9 and luminosity classes III, IV & V. Wefind that objects with He i features either in emission or absorptionare B3 or earlier. Objects with Mg ii emission but no He i are B2 to B4,while objects with Brgamma emission but no evidence of He i or Mg ii areB5 or later. Na i emission in the spectra of 4 objects appears toindicate that regions of the circumstellar envelopes of these stars mustbe shielded from direct stellar radiation. Systematic trends in the linestrength and profile of Brgamma are seen from early to late spectraltypes which can be understood in terms of differences in the disctemperature and density. 30 percent of the stars do not currently showevidence for line emission. Compared to the emission line stars theseobjects have a significantly lower mean rotational velocity and adistribution of spectral types that is significantly earlier. This canbe explained either as the original misidentification of these objectsas Be stars (i.e. they never had line emission), or as evidence thatstars with lower rotational velocities may be more prone to changesbetween the Be and B phases.
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A representative sample of Be stars . I. Sample selection, spectral classification and rotational velocities
We present a sample of 58 Be stars containing objects of spectral typesO9 to B8.5 and luminosity classes III to V. We have obtained 3670 - 5070Angstroms spectra of the sample which are used to derive spectral typesand rotational velocities. We discuss the distribution of spectral typesand rotational velocities obtained and conclude that there are nosignificant selection effects in our sample.
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Catalogue of H-alpha emission stars in the Northern Milky Way
The ``Catalogue of Stars in the Northern Milky Way Having H-alpha inEmission" appears in Abhandlungen aus der Hamburger Sternwarte, Band XIin the year 1997. It contains 4174 stars, range {32degr <= l() II< 214degr , -10degr < b() II < +10degr } having the Hαline in emission. HBH stars and stars of further 99 lists taken from theliterature till the end of 1994 were included in the catalogue. We givethe cross-identification of stars from all lists used. The catalogue isalso available in the Centre de Données, Strasbourg ftp130.79.128.5 or http://cdsweb.u-strasbg.fr and at the HamburgObservatory via internet.
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UBV beta Database for Case-Hamburg Northern and Southern Luminous Stars
A database of photoelectric UBV beta photometry for stars listed in theCase-Hamburg northern and southern Milky Way luminous stars surveys hasbeen compiled from the original research literature. Consisting of over16,000 observations of some 7300 stars from over 500 sources, thisdatabase constitutes the most complete compilation of such photometryavailable for intrinsically luminous stars around the Galactic plane.Over 5000 stars listed in the Case-Hamburg surveys still lackfundamental photometric data.
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Catalogue of stars in the northern Milky Way having H-alpha in emission
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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UBV photoelectric catalogue (1986). II - Analysis
The UBV photoelectric data of the stars presenting several entries inthe 1986 edition of the UBV catalog have been systematicallyintercompared, and this paper presents a discussion of the stars forwhich discrepancies larger than 0.2 mag were found. Thirty-six probablyvariable stars have been detected, among which 18 are Be stars. Sixtyfurther stars present differences in the V magnitude larger than 0.2mag. Sixteen stars already appear in the NSV catalog. Although manyproblems are probably due to poor observations, new (eclipsing) variablestars may be found in this sample. Complete disagreement is foundbetween the values published from two independent sources in 34 cases. Afirst analysis of the quality of the UBV data shows that 65 percent ofthe differences in the V magnitude and in U-B color, for respectively11,500 and 7200 stars with two sources of data, are smaller than 0.04.The scatter on the B-V index appears to be smaller, since the samepercentage reaches 79 percent.
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UBV Photoelectric Photometry Catalogue (1986). III Errors and Problems on DM and HD Stars
Not Available
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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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Additional Variable Stars in the Northern Luminous Stars Catalogues
Not Available
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A spectrophotometric survey of stars along the Milky Way. IV
In the present paper a catalogue of spectrophotometric quantities,spectral types, monochromatic magnitudes and colour equivalents is givenfor all stars brighter than the magnitude m4400 = 10.5 in aregion of the Milky Way in Perseus. No absorption is found for starscloser than about r = 100 pc. The absorbing clouds are situated atdistances closer than 1 kpc and at about 2.5 kpc in the local arm andthe Perseus arm, respectively. The space between the two arms is freefrom absorption. It is also concluded that the Perseus arm continuesbeyond l = 140 deg, containing not only hydrogen gas but also dust to atleast l = 150 deg), while the content of OB stars decreases abruptly atl = 140 deg.
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Wavelength dependence of polarization. XXVI. The wavelength of maximum polarization as a characteristic parameter of interstellar grains.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974AJ.....79..581C&db_key=AST
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Wavelength dependence of polarization. XXV. Rotation of the position angle by the interstellar medium.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974AJ.....79..565C&db_key=AST
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A new general O type stars catalogue
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973A&AS...12..277G&db_key=AST
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Be stars and galactic rotation.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1968AJ.....73..338C&db_key=AST
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Hγ and He I Lines in 09-B5 Spectra
Not Available
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Emissions-B-Sterne und Galaktische Struktur.
Not Available
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Catalogue d'etoiles O et B.
Not Available
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Spectres infrarouges de quelques etoiles des premiers types entre 6500 et 8800 A.
Not Available
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Photoelectric 4430 A observations of 506 O, B and A stars.
Not Available
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Spectroscopic absolute magnitudes of 571 B stars.
Not Available
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Equivalent widths and halfwidths of the lambda 4388 and lambda 4471 HeI lines, rotational velocities and lambda 4430 central depths for 450O to B5 stars.
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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Die galaktischen Emissions-B-Sterne : (Spectralklassifikation, Photometrie, Entwicklung und Verteilung in der Milchstraszenebene)
Not Available
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Catalogue of stellar spectra classified in the Morgan-Keenan system
Not Available
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Luminous stars in the Northern Milky Way. Part I.
Not Available
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