|The First Ultraviolet and Optical Spectropolarimetry of the B[e] Star HD 50138|
We report the first ultraviolet spectropolarimetry of the B[e] star HD50138, obtained with the Wisconsin Ultraviolet Photo-PolarimeterExperiment aboard the Astro-2 Space Shuttle mission in 1995 March. Thedata cover the spectral range 1500-3200 Å. Spectropolarimetryobtained contemporaneously in the range of 3800-10,000 Å in thevisual-to-near-IR region are presented as well. The presence ofintrinsic polarization is detected from the UV to the near-IR. Strongevidence of a thin gaseous disk around the star is found. An almost flatwavelength dependence of the intrinsic polarization in the opticalspectral region indicates that electron scattering, rather than dustscattering, is the dominant polarizing mechanism, although a smallcontribution due to dust scattering cannot be completely ruled out. Asmall inclination of the disk away from edge-on with respect to the lineof sight is suggested. Comparison with similar polarimetric observationsobtained for different objects that have the same circumstellar geometryshows that the envelope of HD 50138 probably has a rather large densitycontrast between the equatorial and polar regions that does not producea position angle flip like that observed in other objects, notably HD45677.
|Ultraviolet and Visible Spectropolarimetry of the Red Rectangle and HD 44179|
We present the first ultraviolet and visible spectropolarimetry of thebiconical nebula the Red Rectangle and its associated binary HD 44179.These observations were made between 1992 November and 1995 Novemberusing the Faint Object Spectrograph on board the Hubble Space Telescopeand two separate ground-based observations. These new data gives moreclues to the geometrical picture of the region. Previous results havetypically reported linear polarizations in the visible and infrared of1%--2%. We present results that clearly show an increase in thecontinuum polarization shortward of 2000 A into the 10%--15% range. Inaddition, the position angle is seen to rotate by 65 deg in the samewavelength region, probably a result of the bipolar geometry and theexistence of an optically thick equatorial disk. It is also seen thatlines due to Mg II absorption, H alpha emission, and several lines dueto CO are polarized differently than the continuum. There also appear tobe features attributable to OH, which would be extremely unusualconsidering the assumed carbon-rich atmosphere that is present.
|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.
|A critical appraisal of published values of (Fe/H) for K II-IV stars|
'Primary' (Fe/H) averages are presented for 373 evolved K stars ofluminosity classes II-IV and (Fe/H) values beween -0.9 and +0.21 dex.The data define a 'consensus' zero point with a precision of + or -0.018 dex and have rms errors per datum which are typically 0.08-0.16dex. The primary data base makes recalibration possible for the large(Fe/H) catalogs of Hansen and Kjaergaard (1971) and Brown et al. (1989).A set of (Fe/H) standard stars and a new DDO calibration are given whichhave rms of 0.07 dex or less for the standard star data. For normal Kgiants, CN-based values of (Fe/H) turn out to be more precise than manyhigh-dispersion results. Some zero-point errors in the latter are alsofound and new examples of continuum-placement problems appear. Thushigh-dispersion results are not invariably superior to photometricmetallicities. A review of high-dispersion and related work onsupermetallicity in K III-IV star is also given.
|Large and Kinematically Unbiased Samples of G- and K-Type Stars. III. Evolved Young Disk Stars in the Bright Star Sample|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1989PASP..101...54E&db_key=AST
|Large and kinematically unbiased samples of G- and K-type stars. II - Observations of evolved stars in the Bright Star sample. III - Evolved young disk stars in the Bright Star sample|
Four color and RI observations were obtained for a large sample ofG-type and K-type stars in the Bright Star Catalogue. Data are firstpresented for 110 evolved stars. Photometry of evolved young diskpopulation stars have then been calibrated for luminosity, reddening,and metallicity on the basis of results for members of the Hyades andSirius superclusters. New DDO results are given for 120 stars.
|Determination of atmospheric parameters for G and K giants by means of photoelectric indices.|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971A&A....15..123H&db_key=AST
|Catalog of Indidual Radial Velocities, 0h-12h, Measured by Astronomers of the Mount Wilson Observatory|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970ApJS...19..387A&db_key=AST