... The overall globular cluster population is divided by gap in the metallicity function at [Fe/H]=-1.0 into two discrete groups with well-defined maxima at [Fe/H]=-1.60?0.03 dex, and -0.60?0.04 dex. ... Clusters with extremely blue horizontal branches occupy a spherical volume of radius ~ 9 kpc, have high rotational velocities ( V rot =77?33 km/s), have substantial and equal negative radial and vertical metallicity gradients, and are, on average, the oldest group (the old-halo subsystem). ...

... Dept. for Physics of Stars&Galaxies . ... Investigation of physical characteristics and evolution of galaxies with active star formation, according to observations at telescopes in the world's largest X-ray, ultraviolet, visible, infrared and radio wavelengths of electromagnetic radiation. ... The analysis of stellar spectra considering deviations from LTE, the evolution and definition of the physical characteristics of stars of late spectral classes.. ... Stars . ... Star clusters of the Galaxy . ...

Stellar Clusters are very useful laboratories for empirically studying stellar evolution. ... All cluster stars are at the same distance . All cluster stars have the same physical age . ... CM diagram Young Cluster In this case we see the Main Sequence fully represented. The blue dots represent massive stars with short main sequence lifetimes. ... Thus, identifying the most massive star which is still on the main sequence is an effective means of determining the age of a stellar cluster. ...

... Programme . ... Abstract: Globular clusters can probe the formation history of galaxies by providing evidence for the chemical evolution and major episodes of star formation in their host galaxies, by examining their kinematic signatures, as well as their structural parameters. ... The giant elliptical NGC 5128 (Centaurus A), at a mere 4 Mpc away, gives us the only opportunity to study in extensive detail the globular cluster system of a recent merger galaxy. ...

Fundamental parameters and time evolution of mass loss are investigated for post-main-sequence stars in the Galactic globular cluster 47 Tucanae (NGC 104). ... We confirm the cluster's distance as d = 4611+213 -200 pc and age as 12 ТБ 1 Gyr. Horizontal branch models appear to confirm that no more red giant branch mass loss occurs in 47 Tuc than in the more metal-poor Я? Centauri, though difficulties arise due to inconsistencies between the models. ...

... Science . ... Science Users Information > Science Activities > Science in Garching > Research Area: STELLAR POPULATIONS . ... Research Area: STELLAR POPULATIONS . Subject in this research area aim at understanding the stellar content of nearby star clusters and galaxies with the goal of understanding their formation and evolution history. ... Evolution of Galaxies and the ISM Stellar Populations Faculty . ... Planets and Star Formation Stellar Populations Stellar Structure and Evolution Faculty . ...

... galaxies: bulges galaxies: clusters: general galaxies: clusters: individual: . ... star formation statistics stellar content structure Cosmology ( cosmology :) cosmic background radiation ( cosmology :) cosmological parameters cosmology : miscellaneous cosmology : observations cosmology : theory ( cosmology :) dark ages, reionization, first stars ( cosmology :) dark energy ( cosmology :) dark matter ( cosmology :) diffuse radiation ( cosmology :) distance scale ( cosmology :) early Universe (...

... 2000, ApJ, 537, L49 . ... F. Palla . Invited Talk at the IAU Symposium 200 "The formation of binary stars" eds. R.D. Mathieu and H. Zinnecker (ASP Conf. Ser.) in press . Optical follow-up of ROSAT discovered candidate members of the open cluster Coma Berenices . ... 2000, A , in press . ... 2000, ApJ, in press . ... 2000, ApJ, in press (Sept. ... 2000, ApJ Lett., in press . ... Click to examine publications from other years . ... Star Formation Group . ... Arcetri Home Page . ...

... We address a question if globular clusters (GC) in a protogalaxy could for some time evolve chemically as isolated systems, enriching themselves with heavy elements produced in first supernova events that follow initial star formation. We determine both the critical mass of a protoglobular cluster that is needed to retain the ejecta of the very first supernova, and the critical energy (i.e., number of supernovae) that is needed to expel the residual gas from a cluster of a given mass. ...

Teaching courses . for student of the Department of Astrophysics and Stellar Astronomy . ... Geophysics and physics of the planets (Kurt, Panteleev) . ... Close Binary Stars . ... Solar Physics . ... This is introductory course for students of the third year of education which are familiar with elementary astronomy and general physics. ... The one-year course includes theory of radiation transfer, theory of internal stellar structure with account of binary systems with compact comapnions. ...

Some astronomers ignore low-mass stars because they aren t very bright. However, stars with initial masses between about 0.8 Msun and 8 Msun (AGB stars) play an important role as the main site of the slow neutron capture (s-)process, which produces roughly half of the elements heavier than iron. ... From this work, we will see have a better understanding of AGB nucleosynthesis, the chemical evolution of globular clusters, and the properties of helium-rich stars. ...

... Structure of Data . ... Catalog . ... In SAI OCL Catalog, we introduce our work on investigation of the Milky Way system of open star clusters. The main goal of our study is a search for new clusters using huge surveys. 168 new clusters have been already discovered by us using J,H,Ks data from 2MASS point source catalog. ... For 141 new clusters, we found their physical parameters using J,H,Ks data from 2MASS catalog and, for a number of clusters, our UBVRI CCD observational magnitudes. ...

The very metal-poor local dwarf galaxies - the analogs of primordial galaxies in young Universe . ... The goal of this project is the study of the properties of the local eXtremely Metal-Deficient (XMD) dwarf galaxies. ... S.A. Pustilnik, J.-M. Martin . ... Pustilnik S.A. "Dark galaxies" and local very metal-poor gas-rich galaxies: possible interrelations, in: Dark Galaxies and Lost Baryons, Edited by J.Davies and M.Disney, Proceedings of IAU Symposium No. 244, held 25-30 June, 2007 in Cardiff, UK. ...

... Figure: Massive binary evolutionary track. ... A short glance to this track is sufficient to understand that there are a lot of evolutionary scenario parameters, which affect different stages of the binary evolution. Fortunately, a very limited number of parameters has effect on the compact binary merging rate. ... The most important (and practically unique) parameter changing the galactic binary NS merging rate is the distribution of an additional (kick) velocity imparted to NS at birth. ...

... The perceptron structure, on the basis of which the database is built, is defined by a number of the input and output parameters and a required accuracy. ... The output perceptron data are the expansion coefficients of the scattering matrix elements in series of the generalized spherical functions. ... As the cluster structure depends on the generation conditions the expansion coefficients were averaged over 5--7 realizations of the clusters (for N . ... is the coefficient number. ...

... 05/09/2013 Galaxy Evolution over Five Decades - Cambridge 2013 Nuclear activity and environment Effect of environment on AGN is not completely clear yet. ... 05/09/2013 Galaxy Evolution over Five Decades - Cambridge 2013 Effect of the mass Mass slices ­ optical and radio AGN overall interaction one-on-one interaction relative location 05/09/2013 Galaxy Evolution over Five Decades - Cambridge 2013 Stratified study Stratifed study that considers several strata of mass. ...

... Stellar cinders . Born-again stars . ... Heavyweight Stars . ... What will happen inside the Sun and why? ... These are questions about "stellar evolution", the history of stars as they are transformed by nuclear processes deep inside. ... Most of what we know about stellar evolution comes from computer models of stars. ... We learn about the evolution of high-mass stars from HR diagrams of young galactic open clusters, and the evolution of low-mass metal-poor stars from old globular clusters. ...

... 8, ``Celestial Mechanics'', 2002 Expansion of the Hamiltonian of the planetary three--body problem into Poisson series in all elements using Poisson series processor PSP E. D. Kuznetsov 1 , K. V. Kholshevnikov 2 , A. V. Greb 3 1 Astronomical Observatory of Urals State University, Ekaterinburg The first step to solve it involves expansion of the corresponding Hamiltonian into Poisson series in all elements. ... As to osculating elements we deal with two systems of them. ...

... LMC Project Outline . NGC 1818 Initial Results . ... The Large Magellanic Cloud (LMC) is uniquely suitable for the study of massive star clusters at all stages of evolution. By combining HST observations of these clusters with N-body models we hope to understand the origin and evolution of rich star clusters in our own Galaxy, in the LMC, and beyond. ... We aim to combine our HST observations with N-body models to understand the formation and evolution of globular clusters. ...

The new view on the population of Galactic open clusters A.E.Piskunov1, N.V.Kharchenko2, S.RЖser3, E.Schilbach3, R.-D.Scholz4 1 2 3 4 Institute of Astronomy, Moscow, Russia Main Astronomical ... Observatory, Kiev, Ukraine Astronomisches Rechen-Institut, Heidelberg, Germany Astrophysikalisches Institut Potsdam, Germany What are open clusters and what do they teach us Groups of Population I ... Cluster complexes: OCC-1 = Gould's Belt cluster complex? ...