Quantitative Stellar Spectral Classification. IV. Application to the Open Cluster IC 2391
In this work we perform the first test of a stellar spectralclassification method (Stock & Stock 1999) by applying it to earlytype stars. The sample of stars are the members of the open cluster IC2391 that have high-resolution spectra available in the UVES Project ofParanal Observatory. We show that, in general, absolute magnitudes M_Vand intrinsic colors (B-V)_0 can be recovered within the uncertaintiesstated in the original calibration (˜ 0.4 for the magnitudes and˜ 0.03 for the colors). This accuracy allows us to estimatedistances and to infer membership of individual stars to obtain anaverage distance to the cluster of 156+/-24 pc, which is in goodagreement with previously reported determinations. Finally, we identifyand discuss the real strengths and limitations of this method and wesuggest how it can be improved for future studies.
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Chemical Composition in Fast Rotators Main Sequence Stars
Using public data of the Ultraviolet and Visual Echelle SpectrographParanal Observatory Project (UVES) the projected rotational velocities,v sin i, for 16 stars in the field of the galactic cluster IC 2391 (oVel Cluster) were obtained using the method of the Fourier transform(FT). We found that only 12 of these objects are cluster members andseparating them in two sets (main sequence stars and evolved stars) acorrelation of the rotation velocity with the effective temperature wasfound, indicating a nearly equal orientation of the rotation axis forthe member stars. The ratios N/C and O/C obtained for the main sequencestars increase with v sin i and show evidence of mixing induced byrotation.
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Open clusters with Hipparcos. I. Mean astrometric parameters
New memberships, mean parallaxes and proper motions of all 9 openclusters closer than 300 pc (except the Hyades) and 9rich clusters between 300 and 500 pc have been computed using Hipparcosdata. Precisions, ranging from 0.2 to 0.5 mas for parallaxes and 0.1 to0.5 mas/yr for proper motions, are of great interest for calibratingphotometric parallaxes as well as for kinematical studies. Carefulinvestigations of possible biases have been performed and no evidence ofsignificant systematic errors on the mean cluster parallaxes has beenfound. The distances and proper motions of 32 more distant clusters,which may be used statistically, are also indicated. Based onobservations made with the ESA Hipparcos astrometry satellite
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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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Radial velocities in the open cluster IC 2391
Radial velocities have been determined for 31 stars in the field of theopen cluster IC 2391, and the percentage of probable radial-velocityvariables is derived. The orbit of one previously known spectroscopicbinary is improved, and the existence of two double-line binaries isconfirmed. The membership to the cluster and the average cluster radialvelocity are discussed and the incidence of short-period binaries amongthe Main-Sequence members of IC 2391 is compared with the incidence forother clusters with similar average axial rotation of its members.
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Axial rotational velocities in the open cluster IC 2391
Projected rotational velocities have been determined for the members ofthe open cluster IC 2391. The results are discussed in the context ofthe statistical relation between axial rotation and percentage ofbinaries found by Abt (1962) for open clusters and associations.
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Spectral morphology in the open cluster IC 2391
Thirty-one stars brighter than B = 10 in the field of the open clusterIC 2391 are classified on the basis of the mean and MK dispersion. Byusing only normal stars of the main sequence and the absolute visualmagnitudes taken from the calibration made by Garrison (1978), adistance modulus of 5.9 + or - 0.07 (p.e.) magnitudes has been obtainedwhich corresponds to a distance of about 150 pc. A new Am star has beendiscovered, and the presence of two more, discovered earlier, has beenconfirmed. The spectra of the Silicon star HD 74535 and of a Si-Cr-Srobject are characterized.
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Relative radial velocities from objective prism spectra in the region of nine southern open star clusters and a star field at Eta Carinae
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1980A&AS...41..245G&db_key=AST
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Polarization measurements of 313 nearby stars
The linear polarization of 313 low galactic latitude stars has beenmeasured. With few exceptions all program stars have a spectral typelater than B9 and are within 600 parsec of the sun. 181 stars aresituated at the southern sky and 132 at the northern sky.
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Stellar spectra in galactic cluster IC 2391
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1965MNRAS.129..411B&db_key=AST
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