We present a catalog of mean proper motions and membership probabilities of individual stars for optically visible open clusters, which have been determined using data from the UCAC4 catalog in a homogeneous way. The mean proper motion of the cluster and the membership probabilities of the stars in the region of each cluster were determined by applying the statistical method in a modified fashion. In this study, we applied a global optimization procedure to fit the observed distribution of proper motions with two overlapping normal bivariate frequency functions, which also take the individual proper motion errors into account. For 724 clusters, this is the first determination of proper motion, and for the whole sample, we present results with a much larger number of identified astrometric member stars. Furthermore, it was possible to estimate the mean radial velocity of 364 clusters (102 unpublished so far) with the stellar membership using published radial velocity catalogs. These results provide an increase of 30% and 19% in the sample of open clusters with a determined mean absolute proper motion and mean radial velocity, respectively.

Aims. Open clusters are essential tools for understanding Galactic structure, as well as stellar evolution, because they are distributed over the whole Galactic plane, and because their ages, distances, and reddening can be determined. The values of derived cluster fundamental parameters can vary greatly because of the often subjective nature of both the isochrone fitting technique and member star selection. To minimize the subjectivity in the selection of stars and to improve the fitting procedure, our group has developed a nonparametric method that estimates the membership likelihood for apparent cluster stars. Methods. The cluster member selection method is based on the star position relative to the cluster center, the density of stars in the color-magnitude diagram (which can be multidimensional), the photometric errors, and the limiting magnitude of observations. We use this method, together with the global optimization tool developed in our previous articles, to fit theoretical isochrones to open cluster photometric data, making use of UBV and 2MASS data sets. Results. Using this likelihood estimation as a weight in the fitting procedure, we show that the method is robust in that it assigns low weights to most contaminating stars and high weights to the stars that are likely cluster members. Our results show that the fundamental parameters determined using 2MASS data agree with those from UBV data when both are determined from the global optimization fitting method, however, the analysis of the open cluster Dias 6 indicates that a revision of the determined parameters might be required for some cases.

We report the results of a statistical analysis performed with the four foregroundcleaned Planck maps by means of a suitably defined local-variance estimator. Our analysis shows a clear dipolar structure in Planck's variance map pointing in the direction (l, b) (220 • , −32 • ), thus consistent with the North-South asymmetry phenomenon. Surprisingly, and contrary to previous findings, removing the CMB quadrupole and octopole makes the asymmetry stronger. Our results show a maximal statistical significance, of 98.1% CL, in the scales ranging from = 4 to = 500. Additionally, through exhaustive analyses of the four foreground-cleaned and individual frequency Planck maps, we find unlikely that residual foregrounds could be causing this dipole variance asymmetry. Moreover, we find that the dipole gets lower amplitudes for larger masks, evidencing that most of the contribution to the variance dipole comes from a region near the galactic plane. Finally, our results are robust against different foreground cleaning procedures, different Planck masks, pixelization parameters, and the addition of inhomogeneous real noise. IntroductionThe temperature fluctuations of the Cosmic Microwave Background radiation (CMB), recently released by the Planck collaboration [1], confirmed with outstanding precision the concordance cosmological model, ΛCDM [2][3][4]. Such exquisite set of cosmological information allows us to test two fundamental properties of the universe expected after the standard inflationary phase [5][6][7][8], namely that the CMB field is, at large-angles, nearly Gaussian and statistically isotropic (see, e.g., [9, 10] and refs. therein).Previous studies using WMAP data indicate significant departure from either gaussianity or statistical isotropy at the largest angular scales -an unexpected result in the ΛCDM model , though possibly disputable [58]. These phenomena, also called anomalies, have been now confirmed with similar high confidence levels, ∼ 3σ, by the Planck collaboration with CMB foreground-cleaned maps [10]. On the other side, only small magnitude Gaussian deviations from primordial origin have been detected in Planck data [59,60]. However, there are more potential sources of non-Gaussianity (NG) in the CMB data than just primordial NG [61][62][63][64][65][66]. These include galactic foregrounds remnants and secondary anisotropies coming from processes after the last scattering surface [60,[67][68][69][70][71][72][73][74][75][76][77][78][79][80][81][82]. In particular, Gaussian analyses for large angular scales are delicate because galactic foregrounds contaminations are not completely understood and, as a consequence, galactic cut-sky masks are still necessary in CMB data analyses [60]. Monteserín et al. (2008) [83] reported an anomalously low variance distribution in WMAP3 maps at 98.7% CL. Cruz et al. (2011)[84] confirmed this result in WMAP5 and WMAP7 data, also pointing that some regions near the galactic plane present an anomalously high variance (95.6% CL) in the south ecliptic hemisphere. Their ...

The metallicity is a critical parameter that affects the correct determination of fundamental characteristics of a stellar cluster and has important implications in Galactic and stellar evolution research. Fewer than 10% of the 2174 currently cataloged open clusters have their metallicity determined in the literature. In this work we present a method for estimating the metallicity of open clusters via non-subjective isochrone fitting using the cross-entropy global optimization algorithm applied to UBV photometric data. The free parameters distance, reddening, age, and metallicity simultaneously determined by the fitting method. The fitting procedure uses weights for the observational data based on the estimation of membership likelihood for each star, which considers the observational magnitude limit, the density profile of stars as a function of radius from the center of the cluster, and the density of stars in multidimensional magnitude space. We present results of [Fe/H] for nine well-studied open clusters based on 15 distinct UBV data sets. The [Fe/H] values obtained in the ten cases for which spectroscopic determinations were available in the literature agree, indicating that our method provides a good alternative to determining [Fe/H] by using an objective isochrone fitting. Our results show that the typical precision is about 0.1 dex.

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