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HD 200857


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The total-to-selective extinction ratio determined from near IR photometry of OB stars
The paper presents an extensive list of the total to selectiveextinction ratios R calculated from the infrared magnitudes of 597 O andB stars using the extrapolation method. The IR magnitudes of these starswere taken from the literature. The IR colour excesses are determinedwith the aid of "artificial standards" - Wegner (1994). The individualand mean values of total to selective extinction ratios R differ in mostcases from the average value R=3.10 +/-0.05 - Wegner (1993) in differentOB associations. The relation between total to selective extinctionratios R determined in this paper and those calculated using the "methodof variable extinction" and the Cardelli et al. (1989) formulae isdiscussed. The R values presented in this paper can be used to determineindividual absolute magnitudes of reddened OB stars with knowntrigonometric parallaxes.

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.

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.

Catalogue of proper motions in the declination of stars of the Moscow zenith zone.
Not Available

The variability of UV extinction-curve shapes and its impact upon dereddened UV energy distributions
The magnitude-limited survey provided by ANS satellite data is used toinvestigate the global variability of the shapes of UV extinction curvesand the errors these variations introduce into the UV continua ofreddened objects. Results show that although variations in UVextinction-curve shape are largest in regions of dense nebulosity, theerrors incurred by using a mean curve to deredden an energy distributionare still significant. It is suggested that debumping should be avoidedwhenever a reliable E(B-V) is available, and that errors in dereddenedUV colors can be reduced by employing a local mean extinction curve.

The interstellar 217 NM band - A third catalogue of equivalent widths
A catalog of equivalent widths of the 217 nm interstellar absorptionband as well as other parameters characterizing the extinction curve inthe ultraviolet has been compiled for 790 O and B stars. A relativelytight correlation between the equivalent width of the 217 nm band andE(B-V) indicates that the absorber of this band is connected with thepopulation of larger interstellar grains responsible for the visualextinction. The parameter characterizing the amount of extinction in thefar UV is only weakly correlated with E(B-V), a result in accord withthe assumption that a second population of very small grains causes therapid increase of the far-UV extinction.

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.

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.

DQ Cephei, a Delta Scuti star of constant variability
The light curves of many Delta Scuti stars appear variable from cycle tocycle, but this complexity may be only apparent and caused by theinteraction of two or more pulsation modes with definite, constantperiods. The present analysis of differential photoelectric photometryfor the Delta Scuti star DQ Cephei yields two frequencies, 8.0603 and12.6788 c/d, which adjust well to observations covering a span of 29years.

Variable Stars in the Northern Luminous Stars Catalogues
Not Available

Infrared colors and the diffuse interstellar bands
Broad-band infrared photometric measurements have been gathered for 105stars which exhibit diffuse interstellar bands in their spectra. Allnormal stars obey a single reddening law, and a value of R equal to 3.08+ or - 0.15 is derived. This value is consistent with other recentdeterminations of R. The diffuse band indicators, the central depth ofthe 4430-A feature and the equivalent widths of the 5780-A and 6284-Afeatures, show as large a scatter with the infrared color excesses asthey do with E(B - V). No single-valued relation between the colorexcesses and the diffuse band strengths appears to exist. This castsdoubt on whether dust grains which produce the visual and infraredextinctions are the carriers for the diffuse interstellar features.

Structure in the Interstellar-Extinction Curve
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971ApJ...166...65Y&db_key=AST

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

Catalogue d'etoiles O et B.
Not Available

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

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

Sur la loi d'absorption interstellaire
Not Available

Six-color photometry of stars. VIII. The colors of 409 stars of different spectral types
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1956ApJ...123..440S&db_key=AST

Proper motions of 650 bright B-type stars.
Not Available

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

The dependence of interstellar absorption of light on the wavelength
Not Available

Recherches sur la loi d'absorption de la poussière interstellaire et sur le spectre continu des étoiles O et B
Not Available

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

Photoelectric Observations of HD 199908
Not Available

A search for stars of the BET CMa type.
Not Available

A New Short-Period Variable Star, HD 199908
Not Available

Sur la détermination de la grandeur de la discontinuité de Balmer par les méthodes de la photométrie à travers des filtres
Not Available

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

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

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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Osservazione e dati astrometrici

Costellazione:Cigno
Ascensione retta:21h03m52.85s
Declinazione:+55°13'49.1"
Magnitudine apparente:7.163
Distanza:591.716 parsec
Moto proprio RA:-3.6
Moto proprio Dec:-4.5
B-T magnitude:7.778
V-T magnitude:7.214

Cataloghi e designazioni:
Nomi esatti   (Edit)
HD 1989HD 200857
TYCHO-2 2000TYC 3956-925-1
USNO-A2.0USNO-A2 1425-11474971
HIPHIP 103966

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