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Integrated spectral properties of 22 small angular diameter galactic open clusters
Aims.Flux-calibrated integrated spectra of a sample of 22 Galactic openclusters of small angular diameter are presented. With one exception(ESO 429-SC2), all objects have Galactic longitudes in the range208° < l < 33°. The spectra cover the range ≈3600-6800Å, with a resolution of ≈14 Å. The properties of thepresent cluster sample are compared with those of well-studied clusterslocated in two 90° sectors, centred at l = 257° and l =347°. The dissolution rate of Galactic open clusters in these twosectors is examined. Methods: Using the equivalent widths of the Balmerlines and comparing line intensities and continuum distribution of thecluster spectra with those of template cluster spectra with knownproperties, we derive both foreground reddening values and ages. Thus,we provide information independent of that determined throughcolour-magnitude diagrams. Results: The derived E(B-V) values for thewhole sample vary from 0.0 in ESO 445-SC74 to 1.90 in Pismis 24, whilethe ages range from ~3 Myr (NGC 6604 and BH 151) to ~3.5 Gyr (Ruprecht2). For six clusters (Dolidze 34, ESO 429-SC2, ESO 445-SC74, Ruprecht 2,BH 151 and Hogg 9) the foreground E(B-V) colour excesses and ages aredetermined for the first time. The results obtained for the remainingclusters show, in general terms, good agreement with previousphotometric results. Conclusions: The age and reddening distributionsof the present sample match those of known clusters in the two selectedGalactic sectors. The present results would favour a major dissolutionrate of star clusters in these two sectors. Two new solar-metallicitytemplates are defined corresponding to the age groups of (4-5) Myr and30 Myr among those of Piatti et al. (2002, MNRAS, 335, 233). The Piattiet al. templates of 20 Myr and (3-4) Gyr are here redefined.Based on observations made at Complejo Astronómico El Leoncito,which is operated under agreement between the Consejo Nacional deInvestigaciones Científicas y Técnicas de laRepública Argentina (CONICET) and the National Universities of LaPlata, Córdoba and San Juan, Argentina. Tables [see full text]-[see full text] and Appendix are only availablein electronic form at http://www.aanda.org
| CCD photometric search for peculiar stars in open clusters. II. NGC 2489, NGC 2567, NGC 2658, NGC 5281 and NGC 6208
High accurate photometric data in the three filter, narrow-band Deltaa-system for five open clusters (NGC 2489, NGC 2567, NGC 2658, NGC 5281and NGC 6208) are presented permitting one to detect apparent chemicallypeculiar stars. The ages and distances are wide spread to improve thestatistics of peculiar stars in our Milky Way. A total of 235 starswithin these clusters have been observed. We have detected ten apparentpeculiar objects (six with significant positive and four with negativeDelta a-values) in four open clusters. Although three of them within theboundaries of NGC 2567 are probably not members of this cluster. Sinceno Strömgren uvbybeta data are available from the literature,Johnson UBV photometry was used to test and calibrate our photometricdata. The results from a comparison of both systems are excellent. Basedon observations at ESO-La Silla and UTSO-Las Campanas. Tables 4 to 8 areonly available 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/373/153 Figure 1 is onlyavailable in electronic form at http://www.edpsciences.org
| 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
| 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.
| 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.
| 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.
| Analysis of the results of MK classification of 176 stars in 37 southern open clusters
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1979A&AS...37..345F&db_key=AST
| A spectral survey of the southern Milky Way 1 : general description and catalogue 1 (l=306 -318 degrees).
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974A&AS...16..445S&db_key=AST
| Southern open stars clusters. III. UBV-Hbeta photometry of 28 clusters between galactic longitudes 297d and 353d
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973A&AS...10..135M&db_key=AST
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משמש של הקבוצה הבאה
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תצפית ומידע אסטרומטרי
| קבוצת-כוכבים: | קנטאור |
| התרוממות ימנית: | 13h46m36.59s |
| סירוב: | -62°54'34.6" |
| גודל גלוי: | 6.593 |
| מרחק: | 10000000 פארסק |
| תנועה נכונה: | -4.4 |
| תנועה נכונה: | -3.4 |
| B-T magnitude: | 6.801 |
| V-T magnitude: | 6.611 |
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