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A spectroscopic survey for lambda Bootis stars. II. The observational data
lambda Bootis stars comprise only a small number of all A-type stars andare characterized as nonmagnetic, Population i, late B to early F-typedwarfs which show significant underabundances of metals whereas thelight elements (C, N, O and S) are almost normal abundant compared tothe Sun. In the second paper on a spectroscopic survey for lambda Bootisstars, we present the spectral classifications of all program starsobserved. These stars were selected on the basis of their Strömgrenuvbybeta colors as lambda Bootis candidates. In total, 708 objects insix open clusters, the Orion OB1 association and the Galactic field wereclassified. In addition, 9 serendipity non-candidates in the vicinity ofour program stars as well as 15 Guide Star Catalogue stars were observedresulting in a total of 732 classified stars. The 15 objects from theGuide Star Catalogue are part of a program for the classification ofapparent variable stars from the Fine Guidance Sensors of the HubbleSpace Telescope. A grid of 105 MK standard as well as ``pathological''stars guarantees a precise classification. A comparison of our spectralclassification with the extensive work of Abt & Morrell(\cite{Abt95}) shows no significant differences. The derived types are0.23 +/- 0.09 (rms error per measurement) subclasses later and 0.30 +/-0.08 luminosity classes more luminous than those of Abt & Morrell(\cite{Abt95}) based on a sample of 160 objects in common. The estimatederrors of the means are +/- 0.1 subclasses. The characteristics of oursample are discussed in respect to the distribution on the sky, apparentvisual magnitudes and Strömgren uvbybeta colors. Based onobservations from the Observatoire de Haute-Provence, OsservatorioAstronomico di Padova-Asiago, Observatório do Pico dosDias-LNA/CNPq/MCT, Chews Ridge Observatory (MIRA) and University ofToronto Southern Observatory (Las Campanas).
| Two-colour photometry for 9473 components of close Hipparcos double and multiple stars
Using observations obtained with the Tycho instrument of the ESAHipparcos satellite, a two-colour photometry is produced for componentsof more than 7 000 Hipparcos double and multiple stars with angularseparations 0.1 to 2.5 arcsec. We publish 9473 components of 5173systems with separations above 0.3 arcsec. The majority of them did nothave Tycho photometry in the Hipparcos catalogue. The magnitudes arederived in the Tycho B_T and V_T passbands, similar to the Johnsonpassbands. Photometrically resolved components of the binaries withstatistically significant trigonometric parallaxes can be put on an HRdiagram, the majority of them for the first time. Based on observationsmade with the ESA Hipparcos satellite.
| Four-colour photometry of eclipsing binaries. XIIb - TV Cet, light curves, photometric elements and determination of helium content
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1979A&A....72..356J&db_key=AST
| Four-colour UVBY and H-beta photometry of field stars - Double-lined spectroscopic binaries, G type dwarfs and early type FK4 stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977A&AS...29..313O&db_key=AST
| UVBY and H beta photometry of early-type stars in a region at high galactic latitude.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973AJ.....78...47D&db_key=AST
| UBV photometry of early-type stars in two regions at high galactic latitudes
Not Available
| A Finding List of Stars of Spectral Type A7 and Earlier in Regions at High Galactic Latitudes. III. 4 HLF 4
An objective prism survey has been made of stars of spectral type A7 andearlier in a 45 square degree region in the 4 HLF 4 area (l^II =180°, b^II = -45°) as part of an investigation of galacticstructure perpendicular to the galactic plane. The survey reported herewas made with the 4° prism on the Michigan Curtis Schmidt telescopeat Cerro Tololo. A finding list containing positions and spectral typesfor 88 stars is presented with finding charts for the stars too faint tobe included in the Bonner Durchmusterung.
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Pozíciós és asztrometriai adatok
| Csillagkép: | Cet |
| Rektaszcenzió: | 03h06m47.06s |
| Deklináció: | +02°42'52.0" |
| Vizuális fényesség: | 7.969 |
| Távolság: | 408.163 parszek |
| RA sajátmozgás: | -13 |
| Dec sajátmozgás: | -10.1 |
| B-T magnitude: | 8.132 |
| V-T magnitude: | 7.983 |
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