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Catalogs of temperatures and [Fe/H] averages for evolved G and K stars
A catalog of mean values of [Fe/H] for evolved G and K stars isdescribed. The zero point for the catalog entries has been establishedby using differential analyses. Literature sources for those entries areincluded in the catalog. The mean values are given with rms errors andnumbers of degrees of freedom, and a simple example of the use of thesestatistical data is given. For a number of the stars with entries in thecatalog, temperatures have been determined. A separate catalogcontaining those data is briefly described. Catalog only available atthe CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| A catalogue of [Fe/H] determinations: 1996 edition
A fifth Edition of the Catalogue of [Fe/H] determinations is presentedherewith. It contains 5946 determinations for 3247 stars, including 751stars in 84 associations, clusters or galaxies. The literature iscomplete up to December 1995. The 700 bibliographical referencescorrespond to [Fe/H] determinations obtained from high resolutionspectroscopic observations and detailed analyses, most of them carriedout with the help of model-atmospheres. The Catalogue is made up ofthree formatted files: File 1: field stars, File 2: stars in galacticassociations and clusters, and stars in SMC, LMC, M33, File 3: numberedlist of bibliographical references The three files are only available inelectronic form at the Centre de Donnees Stellaires in Strasbourg, viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5), or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| Evolved GK stars near the Sun. 2: The young disk population
From a sample of nearly 2000 GK giants a group of young disk stars withwell determined space motions has been selected. The zero point of theluminosity calibrations, both from the ultraviolet flux (modifiedStroemgren system) and that in the region of 4200 to 4900 A (DDOsystem), show a discontinuity of about a half magnitude at the border ofthe young disk and old disk domains. The population separation is basedon the space velocity components, which are also an age discriminant,with the population interface near 2 x 109 yr, based onmodels with convective overshoot at the core. This age corresponds togiant masses near 1.7 solar mass, near the critical mass separating theyoung stars that do not burn helium in degenerate cores from older starsthat do. Ten percent of both populations show CN anomalies in that thederived value of P(Fe/H) from CN (Cm) and fromFe(M1) differ by more than 0.1 dex and the weak and strong CNstars occur equally in the old disk but the weak CN stars predominate inthe young disk. Peculiar stars, where flux distortions affect theluminosity calibrations, are of the CH+(Ba II) and CH-(weak G band)variety and represent less than 1% of the stars in both populations. Theyoung disk giants are restricted to ages greater than about109 yr, because younger stars are bright giants orsupergiants (luminosity class 2 or 1), and younger than about 2 x109 yr, because the old disk-young disk boundary occurs near1.7 solar mass. The distribution of heavy element abundances, P(Fe/H),for young disk giants is both more limited in range (+/- 0.4 dex) and isskewed toward higher abundances, compared with the nearly normaldistribution for old disk giants. The distribution of (U,V) velocityvectors gives (U,V,W) and their dispersions = (+17.6 +/- 18.4, -14.8 +/-8.4, -6.9 +/- 13.0) and (+3.6 +/- 38.4, -20.7 +/- 27.5, -6.7 +/-17.3)km/s for young and old disk giants, respectively.
| Metal enrichment in elliptical galaxies and globular clusters through the study of iron and H-Beta spectral indices
Chemical evolution of elliptical galaxies and globular clusters isaddressed through a combined study of the iron indices at 5270 and 5335A, and of the H-Beta line strength. The observational database of 74standard stars (both dwarfs and giants) referred to in a previous paper(Buzzoni et al. (1992)) complemented with the data of Faber et al.(1985) and Gorgas et al. (1993) allowed us to explore here Fe and H-Betaindex dependence on stellar temperature, gravity, and metallicity. Thederived fitting functions were then included into Buzzoni's (1989) codefor population synthesis in order to derive expected integrated indicesfor simple stellar populations and compare with observations. Partitionof metals in the current chemical mix of galaxies and globulars has beenconstrained supporting the claim that light alpha elements might beenhanced in the globular cluster metal-poor population. An alternativeconclusion resting on the standard framework with (alpha/Fe) = 0 wouldrequire a systematically larger age, about 18-20 Gyr. Iron and magnesiumin ellipticals are found in average solar but a systematic trend of(Mg/Fe) vs global metallicity does exist with iron more deficient withrespect to magnesium at high Z. We conclude that this effect mightindicate that Fe abundance per unit mass in the galaxies is constant(suggesting a constant rate per unit mass of SN I events) while lightmetals supplied by SNe II should have been more effectively enrichedwith increasing galactic total mass.
| Evolved GK stars near the sun. I - The old disk population
A sample of nearly two thousand GK giants with intermediate band, (R,I),DDO and Geneva photometry has been assembled. Astrometric data is alsoavailable for most of the stars. The some 800 members of the old diskpopulation in the sample yield accurate luminosities (from two sources),reddening values and chemical abundances from calibrations of thephotometric parameters. Less than one percent of the objects arepeculiar in the sense that the flux distribution is abnormal. Thepeculiarity is signaled by strong CH (and Ba II) and weak CH. The CH+stars are all spectroscopic binaries, probably with white dwarfcompanions, whereas the CH- stars are not. A broad absorption band,centered near 3500 A, is found in the CH+ stars whereas the CH- objectshave a broad emission feature in the same region. The intensity of theseabsorptions and emissions are independent of the intensity of abnormalspectral features. Ten percent of the old disk sample have a heavyelement abundance from one and a half to three times the solar value.The distribution of the heavy element abundances is nearly a normal onewith a peak near solar abundance and ranges three times to one sixthsolar. The distribution of the (U, V) velocities is independent of theheavy element abundance and does not appear to be random. Ten percent ofthe old disk stars show a CN anomaly, equally divided between CN strongand CN weak. Several stars of individual astrometric or astrophysicalimportance are isolated.
| The magnesium Mg2 index as an indicator of metallicity in elliptical galaxies
A quantitative calibration of the Mg2 index is attempted deriving ametallicity scale for elliptical galaxies. The dependence of the indexon stellar temperature, gravity, and metallicity has been studiedthrough spectroscopic observations of 87 standards applying the derivedcalibration to models for stellar population synthesis. Buzzoni's (1989)computational code has been used to explore the behavior of the indexversus age, IMF, and metallicity of simple stellar populations,inferring galactic metallicity for the Davies et al. (1987) extensiveobservational database. It appears that ellipticals are old metal-richsystems, with age about 15 Gyr and (Fe/H) = + 0.15. A large spread ofnearly one order of magnitude is, however, derived for metallicity amongsingle galaxies confirming that (Fe/H) is the driving parameter inducingthe color spread in the galaxy population. Evolutionary behavior of Mg2is briefly discussed giving its expected variations at early epochs forcomparison with high-redshift galaxies.
| A catalogue of Fe/H determinations - 1991 edition
A revised version of the catalog of Fe/H determinations published by G.Cayrel et al. (1985) is presented. The catalog contains 3252 Fe/Hdeterminations for 1676 stars. The literature is complete up to December1990. The catalog includes only Fe/H determinations obtained from highresolution spectroscopic observations based on detailed spectroscopicanalyses, most of them carried out with model atmospheres. The catalogcontains a good number of Fe/H determinations for stars from open andglobular clusters and for some supergiants in the Magellanic Clouds.
| 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.
| The Perkins catalog of revised MK types for the cooler stars
A catalog is presented listing the spectral types of the G, K, M, and Sstars that have been classified at the Perkins Observatory in therevised MK system. Extensive comparisons have been made to ensureconsistency between the MK spectral types of stars in the Northern andSouthern Hemispheres. Different classification spectrograms have beengradually improved in spite of some inherent limitations. In thecatalog, the full subclasses used are the following: G0, G5, G8, K0, K1,K2, K3, K4, K5, M0, M1, M2, M3, M4, M5, M6, M7, and M8. Theirregularities are the price paid for keeping the general scheme of theoriginal Henry Draper classification.
| A catalogue of Fe/H determinations, 1984 edition
The present version of the Cayrel de Strobel et al. (1981) catalog ofFe/H abundance ratio determinations contains 1921 values for 1035 stars,which represents an augmentation over the previous publication of 48 and47 percent, respectively. In addition, the literature search conductedis complete up to December, 1983. Stellar metal abundance, effectivetemperature, spectroscopic gravity, spectral type, and photometricindices are covered.
| Radial velocities of southern stars obtained with the photoelectric scanner CORAVEL. III - 790 late-type bright stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1985A&AS...59...15A&db_key=AST
| Lithium in late-type giants. III - The weak G band giants
Li abundances are presented for nine different stars to demonstrate thatthe abundances are consistent with the cosmic value. The observationswere made with the coude telescope and echelle spectrometer on La Silla,covering the Li I 6707 A resonance doublet and the 800 A 2-0 band. Thesurvey included the HD stars 18636, 31274, 36552, 40402, 78146 and 82595and the HR stars 1299 and 4154, all Southern Hemisphere weak FraunhoferG band objects. Both Li-6 and Li-7 were detected in HR 1299. It issuggested that the Li detected in all the stars convected outwardquickly and survived, while C diffused inward and was converted to C-13and N-14. The Li abundances can be observed in both main sequence andred giant stars.
| Status of evolution of F, G, and K field stars contained in the Fe/H abundance ratio catalogue
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1983A&A...119....1C&db_key=AST
| The lithium in weak G-band stars
Available data on Li abundance and CH band weakness in weak G-band starsindicates the existence of a linear relationship between Li and carbonabundance. Weak G-band stars with a high Li abundance are least depletedin C, and weak G-band stars with a relatively low Li abundance have avery low abundance of C. Li production seems to be a necessity after thestar leaves the main sequence and reaches the giant branch, probably byspallation reactions on the surface. Then mixing due to meridionalcirculation on the giant branch might bring out the CN-processedmaterial to the surface, at the same time destroying the surface Li.Thus, both C and Li abundances are depleted together.
| A catalogue of /Fe/H/ determinations
A catalog of iron/hydrogen abundance ratios for 628 stars is compiledbased on 1109 published values. The catalog consists of (1) a table ofabsolute iron abundance determinations in the solar photosphere ascompiled by Blackwell (1974); (2) the iron/hydrogen abundances of 628stars in the form of logarithmic differences between iron abundances inthe given star and a standard star, obtained from analyses ofhigh-dispersion spectra as well as useful stellar spectroscopic andphotometric parameters; and (3) indications of the mean dispersion andwavelength interval used in the analyses. In addition, statistics on thedistributions of the number of determinations per star and the apparentmagnitudes and spectral types of the stars are presented.
| Observations of weak G-band stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978MNRAS.185..585R&db_key=AST
| HD 91805 and the nature of the Bidelman-MacConnell weak-G-band stars
Spectroscopic and photometric observations of the weak-G-band star HD91805 are examined together with intermediate-band photometry of severalBidelman-MacConnell objects. Curve-of-growth and spectrum-synthesisanalyses of HD 91805 are performed to obtain insight into the productsof mixing; the results are found to be very similar to those reported bySneden and Peterson (1977) for HR 6766. Evidence based on theintermediate-band photometry is presented that the majority of theBidelman-MacConnell weak-G-band stars are burning helium in their coressubsequent to the helium core flash. Possible causes of the weak-G-bandanomaly are considered, and it is concluded that carbon depletion due tomeridional circulation requires the least radical departure from nowwell-understood astrophysical processes.
| The strength of the 2.3 MU CO band in weak-G-band stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977PASP...89..660H&db_key=AST
| Some observations of weak-G band stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977PASP...89..222D&db_key=AST
| Double star observations at the Lamont-Hussey Observatory of the University of Michigan at Bloemfontein, South Africa.
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Pozíciós és asztrometriai adatok
| Csillagkép: | Vitorla |
| Rektaszcenzió: | 10h35m10.50s |
| Deklináció: | -43°39'53.0" |
| Vizuális fényesség: | 6.08 |
| Távolság: | 276.243 parszek |
| RA sajátmozgás: | -46.4 |
| Dec sajátmozgás: | 31.6 |
| B-T magnitude: | 7.259 |
| V-T magnitude: | 6.205 |
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