내용
사진
사진 업로드
DSS Images Other Images
관련 글
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
| A study of the open cluster NGC 7209 in the Vilnius photometric system
Photoelectric photometry in the Vilnius seven-colour system is presentedfor the open cluster NGC 7209. In total 96 probable cluster members havebeen measured down to V~14.0. For all stars their spectral types,absolute magnitudes, colour excesses, interstellar reddening anddistances are derived from the Vilnius photometry. The metallicity isestimated to be [Fe/H]=-0.07. In addition, a list of suspected binariesis provided. The reddening across the cluster shows a slight trend alongthe north-south direction. The mean reddening equals E(Y-V)=0.121 [inthe UBV system E(B-V)=0.171] which corresponds to A_V=0.54. The derivedmedian distance for NGC 7209 is 1026+/-30pc (equivalent to the distancemodulus V_0-M_V=10.06+/-0.06). Theoretical isochrone fits to thecolour-magnitude diagram yield an age estimate of 0.45Gyr.
| The studies of proper motions in the regions of open clusters. III - NGC 7209
Relative proper motions of 4290 stars in the region of the open clusterNGC 7209 have been determined from the PDS measurements of 12 Pulkovoand one Tashkent normal astrograph plates. In a 28-arcmin-diametercircle around the cluster 148 stars have membership probabilities Pgreater than 0 percent. The total number of cluster stars obtained byweighting them with membership probabilities reaches 109. The catalog ofproper motions is complete down to m(pg) = 15.1 mag; the limiting valueis 15.6 mag.
| Untersuchungen der offenen Sternhaufen NGC 7092 (M 39), NGC 7209, und NCG [sic] 7243
Not Available
|
새 글 등록
관련 링크
새 링크 등록
다음 그룹에 속해있음:
|
관측 및 측정 데이터
천체목록:
|
