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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).
| Interstellar polarization from observations of A and F stars in high and intermediate galactic latitudes, and from stars in the Mathewson and Ford polarization catalogue
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1986A&AS...64..487K&db_key=AST
| UVBY beta photometry of 210 B, A, and F stars in ten areas centered on extragalactic radio sources at high northern galactic latitudes
As part of a study of the reddening properties of the interstellarmedium at the South Galactic pole and particularly along the southernpart of the galactic plane, a catalog of ubvy beta photometry of 210 B,A, and F stars in 10 areas of equal size covering 160 sq deg atlatitudes higher than +30 deg is presented. Each of the observed areasis centered at radio sources that have emission or absorption in the21-cm line; and the main aim of the study is to obtain color excessesfor a comparison of neutral hydrogen column densities, tentativelyassociated with distinct clouds and with the occurrence of dust in theseclouds. V, (b-y), m1, c1, and beta are presented for the 210 stars.
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Membre dels grups següents:
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Dades d'Observació i Astrometria
| Constel·lació: | Hercules |
| Ascensió Recta: | 16h49m30.08s |
| Declinació: | +05°21'54.3" |
| Magnitud Aparent: | 8.134 |
| Distancia: | 411.523 parsecs |
| Moviment propi RA: | -6.3 |
| Moviment propi Dec: | -14.4 |
| B-T magnitude: | 8.222 |
| V-T magnitude: | 8.142 |
Catàlegs i designacions:
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