Садржај
Слике
Уплоадјуј своје слике
DSS Images Other Images
Везани чланци
A statistical search for supermetallicity in F, G and K stars
High-dispersion and low-resolution data are combined to search forsuper-metal-rich (SMR) FGK stars in the solar neighbourhood and Baade'sWindow. The data are assessed by using statistical analysis, with theirrms errors playing a key role. A star is considered to be SMR if itsvalue of [Fe/H]>+0.2dex, while `borderline' SMR status may beassigned if +0.1<[Fe/H]<=+0.2dex. Borderline SMR status isassigned to μ Leo and three other giants, but no full-fledged SMRgiants are found in either Baade's Window or the solar neighbourhood. Bycontrast, the existence of SMR class IV-V stars turns out to be wellestablished, with values found for [Fe/H] that are as large as ~+0.4dex.It is concluded that this apparent contrast between class IV-V stars andgiants should not be interpreted in astrophysical terms at presentbecause of marked shortcomings in the available data base for giants.Recommendations are made about future research that may cure thisproblem and extend present knowledge about SMR dwarfs.
| Catalogue of [Fe/H] determinations for FGK stars: 2001 edition
The catalogue presented here is a compilation of published atmosphericparameters (Teff, log g, [Fe/H]) obtained from highresolution, high signal-to-noise spectroscopic observations. This newedition has changed compared to the five previous versions. It is nowrestricted to intermediate and low mass stars (F, G and K stars). Itcontains 6354 determinations of (Teff, log g, [Fe/H]) for3356 stars, including 909 stars in 79 stellar systems. The literature iscomplete between January 1980 and December 2000 and includes 378references. The catalogue is made up of two tables, one for field starsand one for stars in galactic associations, open and globular clustersand external galaxies. The catalogue is distributed through the CDSdatabase. Access to the catalogue with cross-identification to othersets of data is also possible with VizieR (Ochsenbein et al.\cite{och00}). The catalogue (Tables 1 and 2) is only available inelectronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr(130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/373/159 and VizieRhttp://vizier.u-strasbg.fr/.
| 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
| SANTIAGO 91, a right ascension catalogue of 3387 stars (equinox J2000).
The positions in right ascension of 3387 stars belonging to the Santiago67 Catalogue, observed with the Repsold Meridian Circle at Cerro Calan,National Astronomical Observatory, during the period 1989 to 1994, aregiven. The average mean square error of a position, for the wholeCatalogue, is +/-0.009 s. The mean epoch of the catalogue is 1991.84.
| Sodium in weak G-band giants
Sodium abundances have been determined for eight weak G-band giantswhose atmospheres are greatly enriched with products of the CN-cyclingH-burning reactions. Systematic errors are minimized by comparing theweak G-band giants to a sample of similar but normal giants. If,further, Ca is selected as a reference element, model atmosphere-relatederrors should largely be removed. For the weak-G-band stars (Na/Ca) =0.16 +/- 0.01, which is just possibly greater than the result (Na/Ca) =0.10 /- 0.03 from the normal giants. This result demonstrates that theatmospheres of the weak G-band giants are not seriously contaminatedwith products of ON cycling.
| A large, complete, volume-limited sample of G-type dwarfs. I. Completion of Stroemgren UVBY photometry
Four-colour photometry of potential dwarf stars of types G0 to K2,selected from the Michigan Spectral Catalogues (Vol. 1-3), has beencarried out. The results are presented in a catalogue containing 4247uvby observations of 3900 stars, all south of δ = -26deg. Theoverall internal rms errors of one observation (transformed to thestandard system) of a program star in the interval 8.5 < V < 10.5are 0.0044, 0.0021, 0.0039, and 0.0059, respectively, in V, b-y, m_1_ ,and c_1_. The purpose of the catalogue, combined with earliercatalogues, is to allow selection of a large, complete, volume-limitedsample of G- and K-type dwarfs, investigate their metallicitydistribution, and compare it to predictions of various models ofgalactic chemical evolution. Future papers in this series will discussthese subjects.
| 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.
| 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.
| 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
|
Додај нови чланак
Линкови у сродству са темом
Додај нови линк
Чланови следећих група \:
|
Посматрања и Астрометриски подаци
| Сазвежђа: | Компас |
| Ректацензија: | 09h05m44.21s |
| Deклинација: | -28°04'59.4" |
| Apparent магнитуда: | 8.593 |
| Даљина: | 1162.791 parsecs |
| Proper motion RA: | -9.5 |
| Proper motion Dec: | -3 |
| B-T magnitude: | 10.042 |
| V-T magnitude: | 8.713 |
Каталог и designations:
|
