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Red giants in open clusters. XIV. Mean radial velocities for 1309 stars and 166 open clusters
Context: Radial velocities have proved to be an efficient method formembership determination if there are at least 2 or 3 red giants in acluster. They are necessary for galactic studies, but are still missingfor many open clusters. Aims: We present the final catalogues of along-term observing programme performed with the two coravelspectrovelocimeters for red giants in open clusters. The main aims wereto detect spectroscopic binaries and determine their orbital parameters,determine the membership, and compute mean velocities for the stars andopen clusters. Methods: We computed weighted mean radial velocities for1309 stars from 10 517 individual observations, including the systemicradial velocities from spectroscopic orbits and for cepheids. Results:The final results are contained in three catalogues collecting 10 517individual radial velocities, mean radial velocities for 1309 redgiants, and mean radial velocities for 166 open clusters among whichthere are 57 new determinations. We identified 891 members and 418non-members. We discovered a total of 288 spectroscopic binaries, amongwhich 57 are classified as non-members. In addition 27 stars were judgedto be variable in radial velocities and they are all red supergiants. Conclusions: The present material, combined with recent absolute propermotions, will permit various investigation of the galactic distributionand space motions of a large sample of open clusters. However, thedistance estimates still remain the weakest part of the necessary data.This paper is the last one in this series devoted to the study of redgiants in open clusters based on radial velocities obtained with thecoravel instruments.Based on observations collected at the Haute-Provence Observatory(France) and on observations collected with the Danish 1.54-m telescopesat the European Southern Observatory, La Silla, Chile. Full Tables [seefull textsee full textsee full textsee full textsee full text] to [seefull textsee full textsee full textsee full textsee full text] are onlyavailable and Tables [see full textsee full textsee full textsee fulltextsee full text] and [see full textsee full textsee full textsee fulltextsee full text] are also 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/485/303
| Absolute proper motions of open clusters. I. Observational data
Mean proper motions and parallaxes of 205 open clusters were determinedfrom their member stars found in the Hipparcos Catalogue. 360 clusterswere searched for possible members, excluding nearby clusters withdistances D < 200 pc. Members were selected using ground basedinformation (photometry, radial velocity, proper motion, distance fromthe cluster centre) and information provided by Hipparcos (propermotion, parallax). Altogether 630 certain and 100 possible members werefound. A comparison of the Hipparcos parallaxes with photometricdistances of open clusters shows good agreement. The Hipparcos dataconfirm or reject the membership of several Cepheids in the studiedclusters. Tables 1 and 2 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| Membership, binarity and metallicity of red giants in the southern open cluster NGC 2354
We present new Coravel radial-velocity observations and photoelectricphotometry in the UBV, DDO and Washington systems for a sample of redgiant candidates in the field of the intermediate-age open cluster NGC2354. Photometric membership probabilities show very good agreement withthose obtained from Coravel radial velocities. The analysis of thephotometric and kinematical data allow us to confirm cluster membershipfor 9 red giants, one of them being a spectroscopic binary, while 4confirmed spectroscopic binaries appear to be probable members. We havealso discovered 4 spectroscopic binaries not belonging to the cluster. Amean radial velocity of (33.40 +/- 0.27) km s(-1) and a mean reddeningE(B-V) = 0.13 +/- 0.03 were derived for the cluster giants. NGC 2354 hasa mean ultraviolet excess = -0.03 +/- 0.01, relativeto the field K giants, and a mean new cyanogen anomaly Delta CN = -0.035+/- 0.007, both implying [Fe/H] ~ -0.3. The moderately metal-poorcharacter of NGC 2354 is confirmed using five different metal abundanceindicators of the Washington system. The cluster giant branch is formedby a well defined clump of 7 stars and 4 stars with high membershipprobabilities seem to define an ascending giant branch. The whole redgiant locus cannot be reproduced by any theoretical track. Based onobservations collected with the Danish\protect\linebreak 1.54-mtelescope at the European Southern Observatory, La Silla (Chile); atComplejo Astronómico El Leoncito, which is operated underagreement between the Consejo Nacional de InvestigacionesCientíficas y Técnicas de la República Argentinaand the National Universities of La Plata, Córdoba, and San Juan,Argentina, and at Cerro Tololo Inter-American Observatory, NationalOptical Astronomy Observatories, operated by the Association ofUniversities for Research in Astronomy, Inc., under contract with theNational Science Foundation.
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Osservazione e dati astrometrici
| Costellazione: | Cane Maggiore |
| Ascensione retta: | 07h14m30.69s |
| Declinazione: | -25°48'11.6" |
| Magnitudine apparente: | 9.99 |
| Moto proprio RA: | 22.1 |
| Moto proprio Dec: | -21.6 |
| B-T magnitude: | 11.288 |
| V-T magnitude: | 10.098 |
Cataloghi e designazioni:
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