Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I.
We have embarked on a project, under the aegis of the Nearby Stars(NStars)/Space Interferometry Mission Preparatory Science Program, toobtain spectra, spectral types, and, where feasible, basic physicalparameters for the 3600 dwarf and giant stars earlier than M0 within 40pc of the Sun. In this paper, we report on the results of this projectfor the first 664 stars in the northern hemisphere. These resultsinclude precise, homogeneous spectral types, basic physical parameters(including the effective temperature, surface gravity, and overallmetallicity [M/H]), and measures of the chromospheric activity of ourprogram stars. Observed and derived data presented in this paper arealso available on the project's Web site.
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Stellar encounters with the solar system
We continue our search, based on Hipparcos data, for stars which haveencountered or will encounter the solar system(García-Sánchez et al. \cite{Garcia}). Hipparcos parallaxand proper motion data are combined with ground-based radial velocitymeasurements to obtain the trajectories of stars relative to the solarsystem. We have integrated all trajectories using three different modelsof the galactic potential: a local potential model, a global potentialmodel, and a perturbative potential model. The agreement between themodels is generally very good. The time period over which our search forclose passages is valid is about +/-10 Myr. Based on the Hipparcos data,we find a frequency of stellar encounters within one parsec of the Sunof 2.3 +/- 0.2 per Myr. However, we also find that the Hipparcos data isobservationally incomplete. By comparing the Hipparcos observations withthe stellar luminosity function for star systems within 50 pc of theSun, we estimate that only about one-fifth of the stars or star systemswere detected by Hipparcos. Correcting for this incompleteness, weobtain a value of 11.7 +/- 1.3 stellar encounters per Myr within one pcof the Sun. We examine the ability of two future missions, FAME andGAIA, to extend the search for past and future stellar encounters withthe Sun.
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The ROSAT all-sky survey catalogue of optically bright main-sequence stars and subgiant stars
We present X-ray data for all main-sequence and subgiant stars ofspectral types A, F, G, and K and luminosity classes IV and V listed inthe Bright Star Catalogue that have been detected as X-ray sources inthe ROSAT all-sky survey; several stars without luminosity class arealso included. The catalogue contains 980 entries yielding an averagedetection rate of 32 percent. In addition to count rates, sourcedetection parameters, hardness ratios, and X-ray fluxes we also listX-ray luminosities derived from Hipparcos parallaxes. The catalogue isalso available in electronic form via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
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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.
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Catalog of BV magnitudes and spectral classes of 6000 stars
The present catalog, compiled at the Abastumani Observatory, contains BVmagnitudes and spectral classes of about 6000 stars up to V(lim) = 13.0min five circular areas of 18 sq deg located near the salactic-equatorplane. The catalog is intended for star-statistics studies ofstar-formation regions.
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Catalogue of the energy distribution data in spectra of stars in the uniform spectrophotometric system.
Not Available
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A sample of solar-type stars of known age
A sample of field F and G dwarfs of known ages is presented. All thedwarfs are secondaries of visual binaries in which the temperature andgravity of the hotter primary has been estimated from Stromgrenphotometry, and its age derived from reference to isochrones. This ageis taken to apply to the secondary. Even in the case of F-typesecondaries, which themselves have measured Stromgren indices, it ismuch better to estimate ages from the primaries as it is demonstratedthat use of isochrones to determine age of stars not far evolved fromthe main sequence can lead to significant systematic overestimates ofages when the photometric measurements have typical random errors. Anumber of systems in which photometry is available for both componentshave primaries which appear much younger than the secondaries,suggesting a need for further investigation.
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Uvby-Beta Photometry of Equatorial and Southern Bright Stars - Part Two
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1980A&AS...42..311H&db_key=AST
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Photographic measures of double stars. II
Measures are presented for 302 double stars photographed on 657 plateswith the 36-in. Lick refractor in the period between 1945 and 1962. Thedata provided include the observing epochs, the rectangular coordinatesof the secondary components with reference to the respective primaries,the mean errors of a single measurement, the computed mean errors, thedouble-star separations, and the position angles both for the observingepoch and reduced to the equator of 2000. An additional 561 unmeasuredplates of acceptable quality obtained between 1948 and 1960 are listed.
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Spectral classification and UBV H BET photometry.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977ApJ...213..105D&db_key=AST
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Lithium abundance in stellar atmospheres
Data on the lithium abundance in the atmospheres of 491 stars arecompiled and reduced to a single system. The lithium abundances of thesestars are shown to differ by more than a factor of 1 million, and thedependence of lithium abundance on spectral type is determined forvarious groups of stars. It is found that cooler stars have lowerlithium abundances than hotter stars and that young stars have higherabundances than old stars. Data on the Li-6/Li-7 isotope ratio in theatmospheres of 30 stars are presented which indicate that Li-6 is notobserved in most cases and that the exceptions comprise magneticvariable stars with Li-6/Li-7 ratios of 0.10 to 2.00. It is concludedthat the observational results as a whole are satisfactorily explainedby the hypothesis that the same high lithium abundance characterized allstars at birth but then decreased in the course of evolution due tointermixing of matter.
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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
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Observations of the Lithium Content of Stars in Visual Binary Systems
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1966ApJ...145..759W&db_key=AST
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The Spectra and Axial Rotational Velocities of the Components of 116 Visual Double-Star Systems.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1963ApJ...138..118S&db_key=AST
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Three-color photometry of the components in 228 wide double and multiple systems.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1963AJ.....68..483E&db_key=AST
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Recherches sur les Proprietes des Etoiles Doubles ou Multiples Largement Separees EN Relation avec les Problemes d'Evolution. Tabl. IX
Not Available
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Recherches sur les Proprietes des Etoiles Doubles ou Multiples Largement Separees EN Relation avec les Problemes d'Evolution
Not Available
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Micrometer Measures of Double Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1961ApJS....6....1K&db_key=AST
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Classification d'étoiles doubles dans le système à 3 paramètres λ,D, Φb
Not Available
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Diagramme λ D, Pour les populations I et II- Comparsison au diagramme HR
Not Available
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INHABITED SKY
