CNO in evolved intermediate mass stars
In order to investigate the possible influence of rotation on theefficiency of the first dredge-up we determined atmospheric parameters,masses, and abundances of carbon, nitrogen, and oxygen in a sample ofevolved intermediate mass stars. We used high resolution spectra andconducted a model atmosphere analysis. The abundances were calculatedthrough spectral synthesis and compared to the predictions of rotatingand non-rotating evolutionary models. Almost all those objects in oursample where carbon and nitrogen abundances could be determined showsigns of internal mixing. The stars, however, seem to be mixed todifferent extents. Among the mixed stars we identify five in our samplewith abundances in agreement with the non-rotating models, four starsthat seem to be mixed beyond that, and one star that seems to beslightly less mixed than predicted for the first dredge-up. There arealso five stars that seem to be slightly more mixed than expected, buttheir abundances are in marginal agreement with both rotating andnon-rotating models. Such differences in the extent of the mixing arenot predicted by the standard models and imply the action of othermixing mechanisms than solely the convective dredge-up. We alsoidentified for the first time an important correlation between the [N/C]ratio and the stellar mass.
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A catalog of rotational and radial velocities for evolved stars. II. Ib supergiant stars
Rotational velocity vsin i and mean radial velocity are presented for asample of 231 Ib supergiant stars covering the spectral region F, G andK. This work is the second part of the large survey carried out with theCORAVEL spectrometer to establish the behavior of the rotation for starsevolving off the main sequence (De Medeiros & Mayor 1999). Thesedata will add constraints to the study of the rotational behavior inevolved stars, as well as solid information concerning tidalinteractions in binary systems and on the link between rotation,chemical abundance and activity in stars of intermediate masses. Basedon observations collected at the Haute-Provence Observatory,Saint-Michel, France and at the European Southern Observatory, La Silla,Chile Table 1 is only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/395/97
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UBV beta Database for Case-Hamburg Northern and Southern Luminous Stars
A database of photoelectric UBV beta photometry for stars listed in theCase-Hamburg northern and southern Milky Way luminous stars surveys hasbeen compiled from the original research literature. Consisting of over16,000 observations of some 7300 stars from over 500 sources, thisdatabase constitutes the most complete compilation of such photometryavailable for intrinsically luminous stars around the Galactic plane.Over 5000 stars listed in the Case-Hamburg surveys still lackfundamental photometric data.
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Colour excesses of F-G supergiants and Cepheids from Geneva photometry.
A reddening scale for F-G supergiants and Cepheids is presented.Supergiants with low reddenings or in clusters form the basis of thecalibration. In this sense, it is entirely empirical. The data have beenobtained in the Geneva photometric system. Comparisons with otherreddening scales show no disagreement. The only problem is with Fernie'sscale for Cepheids (1990), where a systematic trend exists. Its originis not clear. It is suggested to extend the number of supergiants withindependently obtained colour excesses in order to test the existence ofa possible luminosity dependence of the calibration. A period-colourrelation for Cepheids is deduced, on the basis of the present reddeningcorrections. It gives strong support for V473 Lyr being a secondovertone pulsator.
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Photometric Parameters for Short-Period Cepheids
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996AJ....111.1313E&db_key=AST
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A spectroscopic database for Stephenson-Sanduleak Southern Luminous Stars
A database of published spectral classifications for objects in theStepenson-Sanduleak Luminous Stars in the Southern Milky Way catalog hasbeen compiled from the literature. A total of 6182 classifications for2562 stars from 139 sources are incorporated.
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Uvbyβ photometry of all stars earlier than G0 and brighter than m_pg_~10.3mag in Selected Area 194
Four-colour and Hβ photometry is introduced for 594 stars earlierthan G0 in the Kapteyn's Selected Area 194. The results give V, b-y,m_1_, c_1_, and β on the standard systems, with overall rms errorsfor one observation of one star of 0.009mag, 0.004mag, 0.006mag,0.009mag, and 0.009mag, respectively. The data cover an area of about5deg x 5deg and is intended for an investigation of the distribution ofthe interstellar medium toward the northern part of the SouthernCoalsack and its surroundings. A comparison to earlier results obtainedby other authors has shown that the c_1_ indices obtained for the latetype stars were underestimated, in average, by 0.020mag. Since suchdifference may account for an error of little more than 10% in theestimated stellar distances, a correction was applied to the c_1_ indexof these stars.
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Photometry of F-K type bright giants and supergiants. I - Intermediate band and H-Beta observations
Over 1500 observations of 560 bright giants and supergiants of types F-Kare presented and compared to the observations by Gray and Olsen (1991).The present results include intermediate-band which is slightlydifferent from the Stromgren data by Gray and Olsen due to a differentwidth for the v filter. A systematic difference in m(1) - M(1) withdecreasing temperature is noted in the two H-Beta data sets, and thecorrelations are defined.
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Photometry of F-K type bright giant and supergiants. II - Calibration on indices in terms of luminosity reddening and abundance of F-type stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1991AJ....102.1826E&db_key=AST
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The calibration of the Stromgren photometric system for A, F and early G supergiants. I - The observational data
An empirical calibration of the Stromgren uvby-beta photometric systemfor the A, F, and early G supergiants is being derived. This paperexplains the observational program and the photometric reductiontechniques used and presents a catalog of new Stromgren photometry forover 600 A, F, and G supergiants.
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The distance and structure of the Coalsack. I - Photometric data
The results of UBV and H-beta photometry for 284 stars of spectral typesB to F located in the area of the dark cloud Coalsack are presented.Most of the present stars are brighter than 10.0 mag and are classifiedin the MK system of Houk and Cowley (1975). For each star, the bestvalues for the extinction and distance modulus are provided, withtypical estimated errors of + or - 0.08 mag for the extinction and + or- 0.32 mag for the distance modulus. Possible misclassifications andspectral peculiarities are noted for several of the stars.
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New UBVRI photometry for 900 supergiants
A description is presented of the results obtained in connection with asystematic program of supergiant photometry on the Johnson UBVRI system.During the eight years after the start of the program, almost 1000 starshave been observed, about 400 three or more times each. The originalselection of stars used the spectral type catalog of Jaschek et al.(1964) to choose supergiants. Since observations were possible from bothChile and Canada, no declination limits were imposed, and no particularselection criteria were imposed other than to eliminate carbon stars.These are so red as to require enormous extrapolations of thetransformation equations.
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Catalog of Luminous Stars in the Southern Coalsack Zone
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1982RMxAA...5..183M&db_key=AST
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Estimation of spectral classifications for bright southern stars with interesting Stromgren indices
This paper investigates the degree of success with which uvby photometrycan be applied to predict spectral classifications for 947 A, F, and Gstars brighter than an apparent magnitude of 8.3 and with four-colorindices indicating some kind of interesting, unusual, or peculiarspectrum. One or several possible spectral classifications are estimatedfor each star from photometry alone, double stars are distinguished, andthe estimates are compared with published classifications. The resultsshow that the framework provided by uvby photometry can be extended toinclude most G and K stars, reddened stars, peculiar stars, and certaintypes of double star.
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O stars and supergiants south of declination -53 0.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976AJ.....81..116H&db_key=AST
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Infrared Surveys of the Southern Milky way. I. Suspected Supergiant Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1969ApJ...156L..37A&db_key=AST
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H_alpha Photometry of Late-type Stars. II. F and G Type Dwarf Stars South of the Equator
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1966MNRAS.131..467P&db_key=AST
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