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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Photometric observations of RR Lyrae covering half a century
4403 photographic observations obtained in the years 1943-1950, 2611white light observations from the years 1550-1957, altogether 31794 UBVobservations collected in the years 1958-1981 and 7135 observations madein the Stromgren uvby and Hβ wide/narrow band photometric systembetween 1990 and 1993 are published,
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Stellar spectrophotometric standards. II
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Reduction of Hamilton echelle data at Lick Observatory
The reduction package used to reduce CCD-echelle data from the Hamiltonspectrograph at Lick Observatory is described. The input data requiredfor the reduction package are addressed, and the steps taken to preparefor reducing an observations are discussed. How the echelle orders arelocated and how the spectra are extracted from the echelle image aredescribed, and the corrections for interference fringes which becomesignificant at red wavelengths are examined. The wavelength calibrationis addressed, and flux calibration and merging of individual orders arecovered. Examples of data reduced using these procedures are presented.
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UVby-beta electrophotometry of RR Lyrae stars.
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Energy distributions in the spectra of 10 B to A stars
The energy distributions in the spectra of 10 stars of spectral classesB to A having V magnitude of about 8 m are obtained. The photometricaccuracy in tying in the absolute energy distributions in the stellarspectra to Vega averages no worse than 3-4%, which permits therecommendation of these stars as secondary spectrophotometric standards.
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A UVBY beta photometric study of RR Lyrae stars. I
Results of high-phase-resolution uvby beta photometry of RR Lyrae starsare used to derive effective temperatures, surface gravities and meanabsolute magnitudes, which are important for the use of RR Lyrae starsas distance indicators within the Galaxy. Dereddening of the data wasperformed according to the average of E(b-y) over an orbital period, andeffective temperatures and surface gravities were derived through theuse of color-calibrated atmospheric grids for the metal-poor RRabprogram stars SU Dra, RX Eri and RR Lyr. Application of theBaade-Wesselink method to the data results in values for the meanabsolute magnitudes of these metal-poor stars which average 0.42magnitudes, which is significantly less than the canonical value of 0.6magnitudes.
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The visual surface brightness relation and the absolute magnitudes of RR Lyrae stars. II - RR Lyrae and X ARIETIS
The theoretical surface brightness relation for RR Lyrae stars has beencombined with new VR photometry to determine distances, radii, andabsolute magnitudes for X Arietis and RR Lyrae. For X Arietis, apulsational variation in the radius from 5.06 solar radii to 5.96 solarradii, a distance of 495 + or - 50 pc, and an intensity mean absolutemagnitude of +0.59 + or - 0.25 is obtained. The corresponding quantitiesfor RR Lyrae are 4.81-5.67 solar radii, 263 + or - 39 pc, and anintensity mean absolute magnitude of +0.61 + or - 0.35. The largererrors quoted for RR Lyrae are due to uncertainties arising from theBlazhko effect. Results are discussed in the context of the dependenceof RR Lyrae absolute magnitudes on metal abundance.
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A catalogue of stellar spectrophotometric data
A list of 378 sets of stellar energy distributions for 356 stars basedon photoelectric spectrophotometry is presented. Data from eight sourceshave been transformed to the Hayes-Latham calibration of Alpha Lyrae.The procedure follows that of Breger (1976) and the present list extendsprevious data, especially for stars of earliest and intermediatespectral types.
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UBV Observations of RR Lyr
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Multicolor television photometry of T Tauri stars. I - Observational technique and preliminary results. II - The nature of variability in T Tauri stars
Results are presented for television observations of 17 T Tauri starsusing a seven-color photometric system. Three types of continuumvariability are distinguished: brightness changes in red light,simultaneous active brightness changes in all spectral regions, andbrightness changes that are more pronounced in the UV than in the redregion. The stars characterized by the first type of variability areshown to have significantly higher bolometric magnitudes than the starsexhibiting the other types, and discrepancies between observed energydistributions and spectral types are tentatively attributed toabsorption of light in circumstellar shells. The absolute energy fluxesemitted by the stellar photospheres in the visible region of thespectrum are calculated along with the Balmer-continuum, H-alpha, andH-beta fluxes originating from the circumstellar gas shells. It is foundthat the type of stellar variability depends on circumstellar-shellluminosity in the Balmer continuum.
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Multicolor Photometry of Northern Wolf-Rayet Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1966ApJ...145..724W&db_key=AST
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The Effect of Departures from LTE on the Stellar Continuum Fluxes in the Spectral-Type Range B5-A0
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1966ApJ...144...76S&db_key=AST
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An Analysis of the Absolute Energy Distribution in the Spectrum of RR Lyrae
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1960ApJ...132..417O&db_key=AST
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Standard Stars for Photoelectric Spectrophotometry.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1960ApJ...131..358O&db_key=AST
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A Study of RR Lyrae in Three Colors.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1955ApJ...122..256H&db_key=AST
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Photo-electric observations of RR Lyrae (Errata: 11 270)
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INHABITED SKY
