Contenuti
Immagini
Carica la tua immagine
DSS Images Other Images
Articoli relazionati
Photometric membership and metallicities of red giant candidates in selected open clusters
As part of a long-term project to determine abundances andastrophysical properties of evolved red stars in open clusters, wepresent high-precision DDO photoelectric observations for a sample of 33red giant candidates projected in the fields of nine Galactic openclusters. These data are supplemented with U BV photoelectric photometryof 24 of these stars as well as with CORAVEL radial-velocityobservations for 13 red giant candidates in four of the clusters. Wealso present Washington photoelectric photometry of a small sample ofred giant candidates of the open cluster Ruprecht 97. The likelihood ofcluster membership for each star photometrically observed and for 23additional red giant candidates with U BV and DDO data available in theliterature, is evaluated by using two independent photometric criteria.Nearly 82% of the analysed stars are found to have a high probability ofbeing cluster giants. Photometric membership probabilities show verygood agreement with those obtained from CORAVEL radial velocities. WhileE(B-V) colour excesses were determined from combined B-V and DDOcolours, calibrations of the DDO system were used to derive MK spectraltypes, effective temperatures and metallicities.The derived DDOmetallicities range between values typical of moderately metal-poorclusters ([Fe/H] = -0.19) to moderately metal-rich ([Fe/H] = 0.25) ones.Tables 3, 4, 7-9 are available at the CDS viahttp://cdsarc.u-strasbg.fr/cgi-bin/qcat?J/AN/329.609
| 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
| Yellow evolved stars in open clusters
This paper describes a program in which Galactic cluster post-AGBcandidates were first identified and then analyzed for clustermembership via radial velocities, monitored for possible photometricvariations, examined for evidence of mass loss, and classified ascompletely as possible in terms of their basic stellar parameters. Theintrinsically brightest supergiants are found in the youngest clusters.With increasing cluster age, the absolute luminosities attained by thesupergiants decline. It appears that the evolutionary tracks ofluminosity class II stars are more similar to those of class I than ofclass III. Only two superluminous giant star candidates are found inopen clusters.
| Positions of stars in regions of 14 southern galactic clusters
Positions have been obtained for a total of 3487 stars scattered over 14regions that are centered on each of the southern galactic clusters NGC1981, 2287, 2437, 2451, 2516, 2546, 2547, 2548, 3114, 3532, IC 2391,2395, 2602, and Truempler 10. A frame of reference has been establishedfor each region using ESO Schmidt plates centered on the clusters, witheach plate containing 20-35 measurable Perth 70 stars that are used fordetermining the positions of 200-400 fainter stars within a centralfield of 25 min of arc radius (covering the corresponding 1.5-m plates).
| Evolved stars in open clusters.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976ApJS...30..451H&db_key=AST
| The open clusters NGC 2546, Pi 1, NGC 2579, and Cr 185
Not Available
|
Sottometti un nuovo articolo
Link relazionati
Sottometti un nuovo link
Membro dei seguenti gruppi:
|
Osservazione e dati astrometrici
| Costellazione: | Poppa |
| Ascensione retta: | 08h11m15.59s |
| Declinazione: | -37°39'56.6" |
| Magnitudine apparente: | 8.481 |
| Distanza: | 1250 parsec |
| Moto proprio RA: | -3.7 |
| Moto proprio Dec: | 3.7 |
| B-T magnitude: | 10.016 |
| V-T magnitude: | 8.608 |
Cataloghi e designazioni:
|
