Contents
Images
Upload your image
DSS Images Other Images
Related articles
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/.
| Magellanic Clouds elemental abundances from F supergiants: Revisited results for the Large Magellanic Cloud
With an improved method of the LTE abundance analysis for most elements(Kovtyukh & Andrievsky 1999), the abundances have beenre-investigated in nine F supergiants of the Large Magellanic Cloud. TheNLTE calculations for carbon, oxygen and sodium, based on Kurucz'satmospheric models with an over-all metal deficiency, were carried out.The most important results are the following: - carbon abundance insupergiants is in much better agreement with the carbon abundance of theLMC H Ii regions, oxygen remaining in fair agreement with H Ii regions.The (C/O) ratio is low, lower than solar and the H Ii ratios (a possiblesign of the first dredge-up, or another large-scale mixing event in thesupergiant atmospheres); - the NLTE computations do not show remarkablesodium overabundances in the LMC supergiants, in contrast with theGalactic supergiants; - the mean abundance of iron is found to be [Fe/H]= -0.40, slightly lower than the results of some previous determinationsfor the LMC, but in agreement with the recent result obtained by Korn etal. (\cite{kornet00}), who give [Fe/H] = -0.41. The relative to ironabundance of oxygen [O/Fe] = + 0.01 derived from nine F supergiantsappears to be in excellent accordance with predictions based on thesmooth model of the LMC evolution; - the (alpha /Fe) ratios arecomparable to those found in previous analyses. The surprisingly lowabundance of Mg is even lower in the new analysis, but it is in goodagreement with the relative magnesium abundance in LMC B-stars [Mg/H] =-0.62 determined by Korn et al. (\cite{kornet00}). Sulphur in theprogram supergiants shows the same abundance within an error bar as in HIi regions; - the iron-group elements follow the solar distribution ofthe (M/Fe) ratios; - the heavy elements show enhanced abundances; -significantly larger log g values were obtained than in a previousstudy, resulting in supergiant masses of about 10-20 Msun,which are in excellent agreement with evolutionary calculations. Basedon spectra collected at ESO La Silla, Chile.
| Red supergiants in the LMC - IV: Calibration of intrinsic colours and the HRD
A new calibration of the (B-V)0, (V-R)0 and(V-I)0 colours in the Kron-Cousins system for F to Msupergiants and of the (V-K)0 colours in the SAAO system of Kto M supergiants in the LMC as measures of effective temperature andbolometric correction is given. For F to G supergiants the theoreticalTeff-intrinsic colour- relations given by Lejeune et al.(1997) on the basis of their own model atmospheres agree mostly wellwith our observations. For K to M supergiants, however, their intrinsiccolours are too red in most cases. The relations given by Bessell et al.(1998) based on the model atmospheres of Plez (1997) fit theobservations better, but their synthetic colours are often also too red.The calibration of the bolometric correction is not reproduced well byany of the models. The HRD of the stars shows two distinct groups, onewith log Teff above 3.80 and one with log Teffbetween 3.53 and 3.62. The upper luminosity and therefore the mass limitdepends significantly on effective temperature. The F to G stars haveMbol up to -9.8 mag (corresponding to 45 Msun),while the K to M stars do not exceed - -9.0 mag (corresponding to 31Msun). Neither the Geneva nor the Padova models can fit thepositions of the most luminous and the coolest supergiants. Thediscrepancy between theory and observation increases both withincreasing mass loss rate and overshooting. Best agreement with theobservations is reached by assuming mass loss rates of 2/3 of the deJager et al. (1988) mass loss rates. As shown both by the luminosity andinitial mass function, very luminous (i.e. massive) stars areoverproportionally rare. With -3.73 +/- 0.20 the slope of the initialmass function is very steep in the considered range of 16-35Msun, but confirms the results obtained by Massey et al.(1995) from an extensive study of the field OB stars both in theMagellanic Clouds and the Galaxy.
| 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
| Carbon, nitrogen, oxygen and lithium abundances of six cool supergiants in the SMC.
Carbon, nitrogen and oxygen abundances were derived from high-resolutionspectra of 6 cool supergiants of the Small Magellanic Cloud.Oxygen-to-iron ratios (mean value <[O/Fe]>=~-0.18dex) are found tobe similar to those found in young objects in the LMC and the Galaxy.This result is discussed in terms of chemical evolution. A meandeficiency of the carbon-to-iron ratio of <[C/Fe]>=~-0.3dex and anitrogen-to-iron ratio <[N/Fe]>=~+0.22dex might imply a mixingsignature, which is confirmed by the low ^12^C/^13^C ratio measured inthree stars. In terms of chemical evolution, carbon plus nitrogenabundances have to be considered: in our sample, a mean value of<[(C+N)/Fe]>=~-0.15dex indicates a slight deficiency in carbonplus nitrogen with respect to the Sun, similar to the deficiencies foundin Galactic supergiants and Orion. Lithium has been detected in all theprogram stars, reaching ɛ(Li)=0.6dex for two stars.
| The HIPPARCOS proper motion of the Magellanic Clouds
The proper motion of the Large (LMC) and Small (SMC) Magellanic Cloudusing data acquired with the Hipparcos satellite is presented. Hipparcosmeasured 36 stars in the LMC and 11 stars in the SMC. A correctlyweighted mean of the data yields the presently available most accuratevalues, mu_alpha cos(delta) = 1.94 +/- 0.29 mas/yr, mu_delta = - 0.14+/- 0.36 mas/yr for the LMC. For the SMC, mu_alpha cos(delta) = 1.23 +/-0.84 mas/yr, mu_delta = - 1.21 +/- 0.75 mas/yr is obtained, whereby careis taken to exclude likely tidal motions induced by the LMC. Bothgalaxies are moving approximately parallel to each other on the sky,with the Magellanic Stream trailing behind. The Hipparcos proper motionsare in agreement with previous measurements using PPM catalogue data byKroupa et al. (1994), and by Jones et al. (1994) using backgroundgalaxies in a far-outlying field of the LMC. For the LMC the Hipparcosdata suggest a weak rotation signal in a clockwise direction on the sky.Comparison of the Hipparcos proper motion with the proper motion of thefield used by Jones et al. (1994), which is about 7.3 kpc distant fromthe center of the LMC, also suggests clockwise rotation. Combining thethree independent measurements of the proper motion of the LMC and thetwo independent measurements of the proper motion of the SMC improvesthe estimate of the proper motion of the LMC and SMC. The correspondinggalactocentric space motion vectors are computed. Within theuncertainties, the LMC and SMC are found to be on parallel trajectories.Recent theoretical work concerning the origin of the Magellanic Systemis briefly reviewed, but a unique model of the Magellanic Stream, forthe origin of the Magellanic Clouds, and for the mass distribution inthe Galaxy cannot yet be decided upon. Future astrometric space missionsare necessary to significantly improve our present knowledge of thespace motion of the two most conspicuous galactic neighbours of theMilky Way.
| A uvbyβ photometric calibration of iron abundances in supergiant stars.
A photometric reddening-free calibration for [Fe/H] valid for giant andsupergiant stars of intermediate temperature, has been obtained usingthe Stroemgren uvbyβ system. Galactic supergiants, supergiants inthe Magellanic Clouds and Galactic metal deficient red giants withspectroscopic determinations of [Fe/H] were used as calibrators. Thecalibration can be used to predict [Fe/H] with an accuracy of 0.33 dex,valid for stars with 0.14<[m_1_]<0.70 in the iron abundance range-2.5<[Fe/H]<+0.3. This shows the potential of supergiant stars astracers of iron abundances in other galaxies. Evidence that Galacticluminous F-G stars are intrinsically bluer than their counterparts inthe Magellanic Clouds is offered.
| Chemical evolution of the Magellanic Clouds. VI. Chemical composition of nine F supergiants from different regions of the large Magellanic Cloud.
In an effort to increase the available information on the chemicalcontent of the Magellanic Clouds, we investigated nine F supergiantsfrom the field of the LMC by high-resolution spectroscopy, in order toobtain the elemental abundance ratios for C, O, ?-elements, Fepeak and heavy elements. The stars are widely distributed over the LMC.An LTE analysis has given the following results: 1. All investigatedstars are metal deficient ([Fe/H] value covers the interval from-0.34dex to -0.14dex; mean value: -0.27dex). 2. The iron abundanceappears to be surprisingly uniform, although the stars were chosen indifferent regions of the LMC. The star-to star scatter is within theobservation uncertainty. 3. For all stars[C/Fe]<~0 but still exceedsthe value observed in LMC HII regions by +0.2dex. 4. The [O/Fe] ratio isvery similar to the one found for the Galactic supergiant Canopus, andthe star-to-star scatter is small (?=0.1dex) 5. Sodium does notseem to be enhanced (in average) in the LMC supergiants. 6. Among?-elements Si, S, Ca and Ti are enhanced in LMC supergiants, butMg is slightly underabundant (with respect to Fe) when compared withsolar value. 7. Heavy s- and r- process elements are overabundant by+0.3dex in average. This overabundance could be somewhat smaller for Eu,a pure r- process element.
| Carbon abundances in the LMC globular cluster NGC 1818.
From medium-resolution spectra (~5A) of 5 red supergiants in theglobular cluster NGC 1818 of the Large Magellanic Cloud, we have derivedtheir metallicities through a comparison to a grid of 380 syntheticspectra (Cayrel et al. 1991). The carbon abundances were then derived bycomputing synthetic spectra in the G-band region. A mean metallicity forthe 5 stars is [Fe/H]=~-0.9. The mean carbon abundance isɛ(C)=7.9 for 4 stars, and a lower value of ɛ(C)=7.2 forthe star B26, for which a convective mixing, or exchange of materialwith a companion has possibly occurred.
| Luminosities of yellow supergiants from near-infrared spectra - Calibration through Magellanic Cloud stars
The possibility of using medium resolution spectrograms in the nearinfrared region to determine luminosities of A-G supergiants has beenexplored. A sample of 49 of these stars has been observed in the twoMagellanic Clouds, and using the intensities of the O I 7774 triplet andan index (CP), which is a combination of the Ca II triplet and Paschenlines intensities, a preliminary luminosity calibration, based on LMCstars, has been obtained. Such a calibration predicts reliableluminosities for Galactic supergiants, and offers the advantage of beingcompletely reddening independent. The reddening free CP index combinedwith BVRI color indices has also been used to estimate the interstellarreddenings of Magellanic Cloud stars.
| The chemical composition of Magellanic Cloud Cepheids and nonvariable supergiants
Results of abundance analyses of 14 Cepheids and nonvariable supergiantsin the Magellanic Clouds are presented along with comparison data onfour Galactic objects. Elemental abundances derived include Li, C, N, O,the alpha-elements, the Fe peak, and limited data on the heavy elements.Only HV 5497 in the LMC shows any detectable Li among the Cloud objects.The present CNO data, when combined with previous results, suggest adisparity between the LMC and the SMC supergiants in that the SMC starshave an essentially constant O/Fe ratio, while the LMC stars do not. TheO/Fe ratios within both Clouds are lower than the ratio found inGalactic stars of similar metallicity, but are comparable to the O/Feratios found in Galactic supergiants. For heavier elements, previousresults which indicate the light s- and r-process elements (Sr, Y, Zr)show Galactic ratios with respect to Fe, but that the heavy s- andr-process elements (Ba-Sm) are enhanced in the Clouds, are confirmed.
| Photometric studies of Magellanic Cloud supergiants. I - Mean magnitudes and reddenings. II - Variability
In the first part of this paper, a combination of spectral types for 81LMC and 46 SMC supergiants from the literature with new BVRI photometryyields reddenings and intrinsic colors for these stars. While reddeningsup to E(B-V) of 0.3 are found for the LMC sample, the figure for the SMCappears to be no more than 0.2. The dust/gas ratio in both galaxies isfound to be lower than in the Milky Way. In the second part, individualBVRI photoelectric observations for 88 LMC and 46 SMC intermediatespectral type supergiants are analyzed for variability. It is noted that45 percent of the stars exhibit significant variations, with theincidence of variability decreasing with decreasing luminosity.
| A photometric determination of the metal content for F-G type supergiants in the Large Magellanic Cloud
A VBLUW photometric analysis is used to derive the metal content of some100 F- and G type supergiants in the LMC. Using the empirical locus ofPel in the V-B/B-L diagram in conjunction with the relative dependenceof theoretical colors on the metal abundance, a metal deficiency of1.4-1.6 is found for the LMC stars in comparison with those in the solarneighborhood. With an average UBV system foreground reddening of E(B-V)= 0.05 for the LMC, these stars have a metal content of 0.66 + 0.11,-0.03 of the solar abundance. Agreement is found with the result ofprevious studies. Application to the derivation of the reddenings ofmost of the galactic supergiants is noted.
| Radial velocities of southern stars obtained with the photoelectric scanner CORAVEL. V - 404 F to M supergiant stars in the Large Magellanic Cloud
High accuracy radial velocities have been obtained for 404 F and Msupergiant stars belonging to the LMC using the photoelectric scannerCORAVEL. The observations are presented and the determination of theaccuracy is described. The results are compared to the previous work ofFeast et al. (1960), Ardeberg et al. (1972), and Brunet et al. (1973),and a new determination of the average velocity dispersion in the LMC isgiven. The general trend of the stellar velocities, as compared to theradial velocities of gaseous components, is examined. A systematic shiftof about 6 km/s between velocities of KM and OBA stars is observed,while agreement is excellent with H I velocities. The surfacedistribution of radial velocities shows a tendency of stars to clusterin groups with low intrinsic velocity dispersions. A preliminary meanvelocity dispersion of 5.3 km/s is determined for KM stars.
| Radial velocities from objective-prism plates in the direction of the Large Magellanic Cloud
A catalog is presented of 711 Large Magellanic Cloud (LMC) stars, withattention to the radial velocities of 418 of these. Also given are theradial velocities of 1127 galactic stars in the direction of the LMC, aswell as discussions of the precision of these measurements and of radialvelocity dispersion in different fields.
| VBLUW photometry of Magellanic Cloud super- and hypergiants, made in 1977 up to 1979
VBLUW photometry (Walraven system) is presented of SMC and LMC super-and hypergiants (super-supergiants). The observations were made between1977 and 1979. Also given are the values for V and B-V of the UBV system(with subscript J). The stability of the photometric parameters duringthe last 10-25 years is assessed by considering stars also treated byother investigators.
| DDO Observations of Southern Stars
Not Available
| A deep objective prism survey of two regions in the Large Magellanic Cloud for OB and supergiant stars
Abstract image available at:http://adsabs.harvard.edu/abs/1979A&AS...35..347P
| BVI Photometry of LMC Supergiants
Not Available
| UBV photometry for supergiants of the Large Magellanic Cloud
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1975A&A....43..345B&db_key=AST
| Radial velocities from objective-prism plates in the direction of the Large Magellanic Cloud. List of 398 stars, LMC members. List of 1434 galactic stars, in the LMC direction
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974A&AS...13..173F&db_key=AST
| Rotation et masse DU grand nuage de Magellan.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973A&A....28..165P&db_key=AST
| Large Magellanic Cloud. 2nd list of L. M. C. members and list of galactic stars
Abstract image available at:http://adsabs.harvard.edu/abs/1973A&AS...10..231F
| Additional observations of supergiants and foreground stars in the direction of the Large Magellanic Cloud
Abstract image available at:http://adsabs.harvard.edu/abs/1973A&AS....9..447B
| Spectrographic and photometric observations of supergiants and foreground stars in the direction of the Large Magellanic Cloud
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972A&AS....6..249A&db_key=AST
|
Submit a new article
Related links
Submit a new link
Member of following groups:
|
Observation and Astrometry data
| Constellation: | Schwertfisch |
| Right ascension: | 05h07m14.18s |
| Declination: | -66°03'18.5" |
| Apparent magnitude: | 11.338 |
| Proper motion RA: | 0.3 |
| Proper motion Dec: | 0.6 |
| B-T magnitude: | 12.237 |
| V-T magnitude: | 11.413 |
Catalogs and designations:
|
