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Proper motion determination of open clusters based on the UCAC2 catalogue
We present the kinematics of hundreds of open clusters, based on theUCAC2 Catalogue positions and proper motions. Membership probabilitieswere obtained for the stars in the cluster fields by applying astatistical method uses stellar proper motions. All open clusters withknown distance were investigated, and for 75 clusters this is the firstdetermination of the mean proper motion. The results, including the DSSimages of the cluster's fields with the kinematic members marked, areincorporated in the Open Clusters Catalogue supported on line by ourgroup.
| Astrophysical parameters of Galactic open clusters
We present a catalogue of astrophysical data for 520 Galactic openclusters. These are the clusters for which at least three most probablemembers (18 on average) could be identified in the ASCC-2.5, a catalogueof stars based on the Tycho-2 observations from the Hipparcos mission.We applied homogeneous methods and algorithms to determine angular sizesof cluster cores and coronae, heliocentric distances, mean propermotions, mean radial velocities, and ages. For the first time we derivedistances for 200 clusters, radial velocities for 94 clusters, and agesof 196 clusters. This homogeneous new parameter set is compared withearlier determinations, where we find, in particular, that the angularsizes were systematically underestimated in the literature.
| Luminosity and mass functions of galactic open clusters. II. NGC 4852
We present wide-field deep {UBVI} photometry for the previouslyunstudied open cluster NGC 4852 down to a limiting magnitude I˜24,obtained from observations taken with the Wide Field Imager cameraon-board the MPG/ESO 2.2 m telescope at La Silla (ESO, Chile). Thesedata are used to obtain the first estimate of the cluster basicparameters, to study the cluster spatial extension by means of starcounts, and to derive the Luminosity (LF) and Mass Function (MF). Thecluster radius turns out to be 5.0±1.0 arcmin. The clusteremerges clearly from the field down to V=20 mag. At fainter magnitudes,it is completely confused with the general Galactic disk field. Thestars inside this region define a young open cluster (200 million yearsold) 1.1 kpc far from the Sun (m-M = 11.60, E(B-V) = 0.45). The PresentDay Mass Functions (PDMF) from the V photometry is one of the mostextended in mass obtained to date, and can be represented as a power-lawwith a slope α = 2.3±0.3 and (the Salpeter MF in thisnotation has a slope α = 2.35), in the mass range 3.2 ≤{m}/{mȯ} ≤ 0.6. Below this mass, the MF cannot beconsidered as representative of the cluster MF, as the cluster mergeswith the field and therefore the MF is the result of the combined effectof strong irregularities in the stellar background and interaction ofthe cluster with the dense Galactic field. The cluster total mass at thelimiting magnitude results to be 2570±210 Mȯ.
| Uniform survey of clusters in the southern Milky Way.
Abstract image available at:http://adsabs.harvard.edu/abs/1975AJ.....80...11V
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