7 research outputs found

    Proper Motions and CCD-photometry of Stars in the Region of the Open Cluster Trumpler 2

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    The results of the complex study of galactic open cluster Trumpler 2 are presented. In order to obtain the proper motions the positions of 2600 stars up to the limit magnitude B ~ 16.25 mag in the area 80x80 arcmin around the cluster were measured on 6 plates with the maximal epoch difference of 63 years. The root-mean error of the relative proper motions is 4.2 mas/yr. The catalogue of BV magnitudes of all the stars in the investigated area was compiled. Astrometric selection of the cluster members within the region of R<16 arcmin from the center of the cluster was made by means of the W.Sanders method. In that field 192 stars were found to have the individual membership probability greater then 85%, 148 of them are situated within the +/-3sigma_(B-V) band around the main sequence of the cluster. They are considered to be cluster members by two criteria. The U-B ~ B-V diagram plotted for the astrometrical cluster members by the data taken from the Washington catalogue of the UBV photometry in the galactic cluster fields (Hoag et al.1961) made it possible to redefine the value of the color excess E(B-V)=0.40 mag. The superposition of the MS of the cluster with the ZAMS Schmidt-Kaler leads to the coincidence at the value of the apparent distance module (V-Mv)=10.50 which corresponds to the distance r=725 pc. The luminosity and mass functions of the Trumpler 2 were constructed and the value of the slope Gamma=-1.90+/-0.22 was determined. The cluster age of 8.913x10^7 yr was determined. It is shown that the red giant on the late stage of the evolution (st N.1095) belongs to cluster and indicates the brightness variability. The possibility that the number of both known and recently discovered variables are cluster members was considered. Tables 2,3,3A,5 will be only available in the electronic form.Comment: 14 pages, 7 figure

    Memberships and CM Diagrams of the Open Cluster NGC 7243

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    The results of astrometric and photometric investigations of the open cluster NGC 7243 are presented. Proper motions of 2165 stars with root-mean-square error of 1.1 mas/yr were obtained by means of PDS scanning of astrometric plates covering the time interval of 97 years. A total of 211 cluster members down to V=15.5 mag have been identified. V and B magnitudes have been determined for 2118 and 2110 stars respectively. Estimations of mass (348Mo < M < 522Mo), age (t=2.5x10^8 yr), distance (r=698 pc) and reddening (E(B-V)=0.24) of the cluster NGC 7243 have been made.Comment: 24 pages, 15 figures. Submitted to Astronomy and Astrophysic

    Proper Motions and CCD-photometry of Stars in the Region of the Open Cluster NGC 1513

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    The results of astrometric and photometric investigations of the poorly studied open cluster NGC 1513 are presented. The proper motions of 353 stars with the root-mean-square error of 1.9 mas/yr were obtained by means of the automated measuring complex "Fantasy" scanning of 8 astrometric plates covering the time interval of 101 years. A total of 141 astrometric cluster members have been identified. BV CCD-photometry was made for the stars in a square size 17 arcmin x 17 arcmin centered on cluster. 33 stars with the high reliability were considered to be cluster members by two criteria. The estimation of NGC 1513 age is 2.54 E+08 years. Tables 2 and 3 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/.Comment: 11 pages, 5 figure
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