תוכן
תמונות
הוסף תמונה שלך
DSS Images Other Images
מאמרים קשורים
Spectroscopic Binaries and Kinematic Membership in the Open Cluster NGC 3532
We report spectroscopic observations for bright stars in the opencluster NGC 3532 up to 1 mag below the turnoff point. We compute radialvelocities by cross-correlations and determine spectral types androtational velocities. Using 21 stars identified as certain members, wederive a mean cluster velocity of +3.4+/-0.3 km s-1. Fromradial velocities and angular distances to the cluster center, wecompute membership probabilities for all but two stars that are radialvelocity variables. Only one out of 34 program stars is a clearkinematic nonmember. Three spectroscopic binaries and three additionalpossible radial velocity variables are detected among the 23 starsmeasured more than once. We report the star HD 96609 as a double-linedspectroscopic binary. Using the two-dimensional cross-correlationtechnique TODCOR developed by Zucker & Mazeh, we derive the radialvelocity curves for both components and obtain the orbital parameterswith errors of 0.3% and 0.7% for the projected orbital semiaxis andmasses, respectively. This system is composed of two main-sequence starsin a circular orbit, with a period of 8.19 days. The observationspresented here were obtained at the Complejo Astronómico ElLeoncito (CASLEO), which is operated under agreement between the ConsejoNacional de Investigaciones Científicas y Técnicas de laRepública Argentina (CONICET) and the National Universities of LaPlata, Córdoba, and San Juan.
| 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
| 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
| A catalogue of [Fe/H] determinations: 1996 edition
A fifth Edition of the Catalogue of [Fe/H] determinations is presentedherewith. It contains 5946 determinations for 3247 stars, including 751stars in 84 associations, clusters or galaxies. The literature iscomplete up to December 1995. The 700 bibliographical referencescorrespond to [Fe/H] determinations obtained from high resolutionspectroscopic observations and detailed analyses, most of them carriedout with the help of model-atmospheres. The Catalogue is made up ofthree formatted files: File 1: field stars, File 2: stars in galacticassociations and clusters, and stars in SMC, LMC, M33, File 3: numberedlist of bibliographical references The three files are only available inelectronic form at the Centre de Donnees Stellaires in Strasbourg, viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5), or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| Open cluster chemical composition. 1: Later type stars in eight clusters
Abundance analyses of 36 stars associated with eight open clusters (IC2581, NGC 3532, NGC 5822, NGC 6067, NGC 6087, IC 4725 (M25), IC 4756,and NGC 6882/6885) are presented. The stars are primarily evolved G andK giants and supergiants. Cepheids in NGC 6067, NGC 6087, and IC 4725are included as are non-cluster Cepheids near the clusters NGC 3532, NGC6067, and IC 4725. With the addition of a background K giant in IC 4725,the total number of stars is 40. Elemental abundances derived includeLi, C, N, O, the alpha-elements, the Fe peak, and limited data on theheavy elements. The Na abundances of the sample show a gravitydependence in the sense of an increase in the abundance as the gravitydecreases. The CNO abundances indicate that these objects are processed(on the whole), and that they show the O deficiency previously noted inintermediate mass stars by Luck & Lambert (1981, 1985). There arefour stars in the sample which appear to be unprocessed: two giants andtwo supergiants. There are also two super-Li stars in the sample, one ofwhich is most likely a weak G-band star. It is suggested that thesuper-Li F supergiants could be evolved blue stragglers. The moststriking result of the study is the finding that the (O/Na) ratiocorrelates strongly with the gravity and the stellar mass, thus implyingthat there is a nonstandard additional mixing process affecting thesurface abundances of these stars. A promising candidate for the mixingprocess is the turbulent diffusive mixing process proposed byDenissenkov (1993) which brings Na to the surface and which could alsolead to a modification of the oxygen content.
| Walraven photometry of nearby southern OB associations
Homogeneous Walraven (VBLUW) photometry is presented for 5260 stars inthe regions of five nearby southern OB associations: Scorpio Centaurus(Sco OB2), Orion OB1, Canis Major OB1, Monoceros OB1, and Scutum OB2.Derived V and (B - V) in the Johnson system are included.
| A UBV and DDO astrophysical study of the open cluster NGC 3532
Photoelectric observations in the UBV and DDO systems have been obtainedfor 12 stars on the red giant branch of NGC 3532. A mean reddeningE(B-V) = 0.07 + or - 0.02 has been determined from the red clustergiants. The results show nearly solar metallicity for NGC 3532, andimply that most of the stars are red giants in the core helium burningstage of evolution.
| UBVRI photometry in the open cluster NGC 3532
NGC 3532 is a populous open cluster of intermediate age located a fewdegrees northwest of Eta Carina. The present investigation is concernedwith observations which were conducted at the Las Campanas Observatoryin Chile during the period March-July 1981. A 61-cm telescope and UBVRIphotometer system described by Fernie (1974) were used in theobservations. The results for the cluster stars are listed in a table.Standard stars from the E regions of Cousins were used each night tocarefully determine extinctions and transformations. Attention is givento nightly rms errors for Cousins standards, the B-V color-magnitudediagram for NGC 3532, a V-R color-magnitude diagram for NGC 3532, andcomparisons of V magnitudes and B-V colors for NGC 3532
| The open cluster NGC 3532
NGC 3532 is a large cluster in the Carina region of the southern MilkyWay. Observations in the modified Stromgren and H beta systems have beenobtained for 33 stars. (R,I) photometry for the red stars is listed in atable. The HD and CPD numbers for the 33 stars are also listed togetherwith the numbers assigned by Koelbloed. Attention is given to reddeningand luminosity determinations, the red giants in the cluster region, acomparison of computed and cluster luminosities for some of thecalibrating stars, and age considerations. It is pointed out that theusefulness of NGC 2287 and 3532 for testing stellar models is increasedby the existence of a third, bright cluster of intermediate age, NGC6475.
| Photometric Study of the Southern Open Cluster NGC3532
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1980A&AS...39...11F&db_key=AST
| Three-colour photometry of the three southern open clusters NGC 3532, 6475 (M7), and 6124
Not Available
| Photovisual magnitudes of 219 stars in NGC 3532
Not Available
|
הכנס מאמר חדש
לינקים קשורים
הכנס לינק חדש
משמש של הקבוצה הבאה
|
תצפית ומידע אסטרומטרי
| קבוצת-כוכבים: | שדרית |
| התרוממות ימנית: | 11h04m35.97s |
| סירוב: | -58°45'20.9" |
| גודל גלוי: | 7.655 |
| מרחק: | 209.205 פארסק |
| תנועה נכונה: | -8.6 |
| תנועה נכונה: | 5.8 |
| B-T magnitude: | 8.959 |
| V-T magnitude: | 7.763 |
קטלוגים וכינוים:
|
