Spectral Classification of Stars in A Supplement to the Bright Star Catalogue
MK spectral types are given for about 584 stars in A Supplement to theBright Star Catalogue. These are compared with Hipparcos parallaxes tocheck the reliability of those classifications. The estimated errors are+/-1.2 subtypes, and 10% of the luminosity classes may be wrong.
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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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UvbyHbeta_ photometry of main sequence A type stars.
We present Stroemgren uvby and Hbeta_ photometry for a set of575 northern main sequence A type stars, most of them belonging to theHipparcos Input Catalogue, with V from 5mag to 10mag and with knownradial velocities. These observations enlarge the catalogue we began tocompile some years ago to more than 1500 stars. Our catalogue includeskinematic and astrophysical data for each star. Our future goal is toperform an accurate analysis of the kinematical behaviour of these starsin the solar neighbourhood.
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Radial velocity measurements. IV - Ground-based accompaniment to the HIPPARCOS observation program
The paper presents 396 radial velocities of stars distributed in 19fields of 4 x 4 degrees. The study employs the Fehrenbach objectiveprism method and the same measuring technique used in a previous paper(Fehrenbach et al., 1987).
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Third preliminary catalogue of stars observed with the photoelectric astrolabe of the Beijing Astronomical Observatory.
Not Available
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Radial velocity measurements. I - Ground-based observations of the program stars for the HIPPARCOS satellite
The radial velocities of 272 stars brighter than m(pg) = 8.5 aredetermined by digital microphotometric measurement of plates obtainedwith dispersion 80 A/mm using the Marly slit spectrograph on the 120-cmtelescope of the Observatoire de Haute Provence. The objects wereselected as probable members of the input catalog for the ESA Hipparcosastrometric satellite. The measurement techniques and data-reductionprocedures are described in detail, and the results are presented inextensive tables and graphs and briefly characterized.
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The frequency of Ap-stars with long rotation periods
Light variability was observed over time intervals of months to years inthe stars HD 55540, HD 71066, HD 94660, and HD 187474. The significanceof these results is discussed in terms of the frequency of chemicallypeculiar CP2 stars showing (light) variability with periods longer thanone month. This frequency, relative to the whole CP2 population, mustlie somewhere between 4 and 16 percent. Observations, properlydistributed in time, of a small subgroup of CP2 stars will be sufficientto obtain an accurate ratio of the number of LP-CP2 stars to the totalnumber of CP2 stars. These observations, when continued until theperiodicity is detected, could contribute also to the discussion whetherthese long periods should be identified with the rotation period.
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The improvement of the star positions of the Potsdam PZT catalog
Regular determinations of the right ascension and declination of starswith the aid of a photographic zenith tube (PZT) were begun in ageodetic-astronomical observatory of the German Democratic Republic in1972. Results obtained during the years 1972 and 1973 were used for afirst improvement of stellar positions listed in the Third Catalog(Katalog) of the 'Astronomische Gesellschaft' (Astronomical Society)AGK3. The corrections resulted in a distinct improvement of the accuracyof the positional values. However, the possibility could not be excludedthat the results were still affected by remaining errors with systematiccharacteristics. In order to eliminate the considered deficiencies, newstellar coordinate corrections were computed on the basis of aconsiderably larger data set. The new catalog containing the reviseddata has been called PZT 80, while the data obtained on the basis of thefirst observations are listed in PZT 74. The new catalog is presented inthe appendix.
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Catalogue des étoiles mesurées dans le système photométrique de l'Observatoire de Genève
Not Available
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INHABITED SKY
