Catalog of Galactic β Cephei Stars
We present an extensive and up-to-date catalog of Galactic β Cepheistars. This catalog is intended to give a comprehensive overview ofobservational characteristics of all known β Cephei stars, coveringinformation until 2004 June. Ninety-three stars could be confirmed to beβ Cephei stars. We use data from more than 250 papers publishedover the last nearly 100 years, and we provide over 45 notes onindividual stars. For some stars we reanalyzed published data orconducted our own analyses. Sixty-one stars were rejected from the finalβ Cephei list, and 77 stars are suspected to be β Cepheistars. A list of critically selected pulsation frequencies for confirmedβ Cephei stars is also presented.We analyze the β Cephei stars as a group, such as the distributionsof their spectral types, projected rotational velocities, radialvelocities, pulsation periods, and Galactic coordinates. We confirm thatthe majority of the β Cephei stars are multiperiodic pulsators. Weshow that, besides two exceptions, the β Cephei stars with highpulsation amplitudes are slow rotators. Those higher amplitude starshave angular rotational velocities in the same range as thehigh-amplitude δ Scuti stars (Prot>~3 days).We construct a theoretical HR diagram that suggests that almost all 93β Cephei stars are main-sequence objects. We discuss theobservational boundaries of β Cephei pulsation and the physicalparameters of the stars. We corroborate that the excited pulsation modesare near to the radial fundamental mode in frequency and we show thatthe mass distribution of the stars peaks at 12 Msolar. Wepoint out that the theoretical instability strip of the β Cepheistars is filled neither at the cool nor at the hot end and attempt toexplain this observation.
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Statistics of the Instability Strip of β Cephei Stars
We present a study of the β Cephei instability strip based on asample of 49 stars of this type. After deriving their effectivetemperatures and luminosities from their observed (B-V), (U-B) colorsand parallaxes we find their positions in the HR diagram to be mostlyconfined to the main sequence, and their masses to lie between 7Mȯ and 30 Mȯ. Their distribution on theHR diagram matches well with our previous theoretical instability stripwhich has an upper bound in the luminosity and rather tight boundariesin the effective temperature.
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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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CCD Observations of Short-Period Variables at Middlebury College
The Middlebury College Observatory is equipped with a 0.41-m reflectingtelescope and a CCD imaging camera. Among the observational programs wehave undertaken is the photometric study of short-period variable stars,especially delta Sct variables. There are many short-period (P < 6h)variables with amplitudes of several hundredths of a magnitude orgreater, which are ideal objects for study with CCDs on smalltelescopes, especially in educational settings.
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An Einstein Observatory SAO-based catalog of B-type stars
About 4000 X-ray images obtained with the Einstein Observatory are usedto measure the 0.16-4.0 keV emission from 1545 B-type SAO stars fallingin the about 10 percent of the sky surveyed with the IPC. Seventy-fourdetected X-ray sources with B-type stars are identified, and it isestimated that no more than 15 can be misidentified. Upper limits to theX-ray emission of the remaining stars are presented. In addition tosummarizing the X-ray measurements and giving other relevant opticaldata, the present extensive catalog discusses the reduction process andanalyzes selection effects associated with both SAO catalog completenessand IPC target selection procedures. It is concluded that X-rayemission, at the level of Lx not less than 10 exp 30 ergs/s, is quitecommon in B stars of early spectral types (B0-B3), regardless ofluminosity class, but that emission, at the same level, becomes lesscommon, or nonexistent, in later B-type stars.
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The structure and dynamics of evolved supernova remnants - The IC 443 complex
The extended cloud complex containing the supernova remnant IC 443, theH II region S 249 and members of the Gem OB 1 association is studiedwith IRAS observations at 12, 25, 60 and 100 microns and WSRTobservations at 327 and 1400 MHz and in the 21 cm H I line. IC 443 isshown to consist of three interconnected approximately sphericalsubshells of vastly different radii and centroids. The geometry is fullyconstrained by the structural and kinematic data. Two of these subshellstogether define the usually assumed boundaries of IC 443, while thethird includes the optical filaments which extend beyond the brightnorth-eastern rim. These filaments are shown to have well correlatednonthermal radio counterparts. Physical parameters are derived for theentire complex, individual H II regions and the shocked and recombinedgas within IC 443 from the radio and infrared data. The availableevidence implies that the SNR shock has encountered a pre-existing highdensity shell. It is shown that the system of subshells is fullyconsistent with formation by stellar wind driven bubbles generated byassociation members within the inhomogeneous environment of the complex.
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A catalog of ultraviolet interstellar extinction excesses for 1415 stars
Ultraviolet interstellar extinction excesses are presented for 1415stars with spectral types B7 and earlier. The excesses with respect to Vare derived from Astronomical Netherlands Satellite (ANS) 5-channel UVphotometry at central wavelengths of approximately 1550, 1800, 2500, and3300 A. A measure of the excess extinction in the 2200-A extinction bumpis also given. The data are valuable for investigating the systematicsof peculiar interstellar extinction and for studying the character of UVinterstellar extinction in the general direction of stars for which theextinction-curve shape is unknown.
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Variable Stars in the Northern Luminous Stars Catalogues
Not Available
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H I absorption measurements of seven low-latitude pulsars
The neutral hydrogen absorption spectra of seven low-latitude pulsarsare measured and used to estimate their distances and mean electrondensities along the lines of sight. Calculations made in terms of theSchmidt (1965) galactic rotation model on the basis of the spectralobservations made using the Arecibo 305-m telescope indicate thatpulsars 1919+21 and 1929+10 are within 1.5 kpc of the earth and pulsars2016+28 and 2020+28 are further than 1.3 kpc. Considerations ofabsorption spectra, dispersion and rotation measurements and Stromgrenspheres along the line of sight indicate that PSR 0525+21 isapproximately as distant as the Crab Nebula pulsar (2 kpc), while PSR0540+23 is more distant. Absorption in PSR 0611+22 is found to besimilar to that of the nearby supernova remnant IC 443, but theresemblance may be due to the small change of velocity with distance inthe direction of the anticenter. The dispersion measured and distancesof 32 known pulsars indicates extended regions of enhanced electrondensity in the inner part of the Galaxy and the Gum Nebula, withelectron density elsewhere generally between 0.02 and 0.03/cu cm.Possible sources of the ionization include stellar UV radiation.
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Studies of luminous stars in nearby galaxies. I. Supergiants and O stars in the Milky Way.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978ApJS...38..309H&db_key=AST
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Four-color and H beta photometry of beta CEP stars and their locationin the Hertzsprung-Russel diagram.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1975A&A....41..367S&db_key=AST
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The spectral classification of the beta CEP stars and their location in the theoretical Hertzprung-Russell diagram.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973A&A....22..229L&db_key=AST
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57th Name-List of Variable Stars
Not Available
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Photoelectric 4430 A observations of 506 O, B and A stars.
Not Available
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On Beta Cephei Stars: a Search for Beta Cephei Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1967ApJS...14..263H&db_key=AST
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Vergleich der Spiralstruktur bei frühen galaktischen Sternhaufen H II-Regionen, H I-Regionen und auβergalaktischen Sternsystemen. Mit 4 Textabbildungen
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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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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A Study of the i Geminorum Association.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1960ApJ...132..361H&db_key=AST
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A Catalogue of H II Regions.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1959ApJS....4..257S&db_key=AST
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Interstellar Absorption Lines in Distant Stars. I. Northern Milky way.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1957ApJ...125...42M&db_key=AST
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Line Broadening in the Spectra of o- and Early B-Type Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1956ApJ...124..173S&db_key=AST
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Studies in Galactic STRUCTURE.II.LUMINOSITY Classification for 1270 Blue Giant Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1955ApJS....2...41M&db_key=AST
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The Association i Geminorum.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1955ApJ...121...24C&db_key=AST
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Polarization of Stellar Radiation. III. The Polarization of 841 Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1951ApJ...114..241H&db_key=AST
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A Finding List of O and B Stars of High Luminosity.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1951ApJ...113..141N&db_key=AST
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INHABITED SKY
