... The most powerful and widely used methods to calculate the scattering matrix of a fractal cluster are based on the coupled dipoles methods (e.g. the Discrete Dipole Approximation, DDA) and the theory of light scattering by a cluster of spherical particles [2-4]. ... At present the procedure of calculation of the scattering matrix is well developed for both an oriented cluster of spherical particles and for chaotically oriented clusters of such particles [4]. ...

... Editor's choices for the most educational Astronomy Pictures of the Day about clusters of galaxies: . APOD: 2006 March 21 - The Coma Cluster of Galaxies . ... APOD: 2005 November 22 - A Galactic Collision in Cluster Abell 1185 . ... A prominent example occurs on the left of the above image of the rich cluster of galaxies Abell 1185. ... Recent observations of Abell 1185 have found unusual globular clusters of stars that appear to belong only to the galaxy cluster and not to any individual galaxy. ...

... 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. ...

... Abell 2218: A Galaxy Cluster Lens . ... Almost all of the bright objects in this Hubble Space Telescope image are galaxies in the cluster known as Abell 2218. ... A Sunspot in the New Solar Cycle . ... A new cycle has begun on our Sun. ... Pictured above in a specific color of light emitted by hydrogen is sunspot 10982, one of the first sunspots of the new solar cycle. Three Month Composite of Comet Holmes . ... How has Comet Holmes changed? ... The First Explorer . ...

... BIG BANG COSMOLOGY, GALACTIC CLUSTERS, SPACE DENSITY, UNIVERSE, FRAGMENTATION, HYDROGEN CLOUDS, INTERSTELLAR GAS, SPATIAL DISTRIBUTION, VOIDS . ... The fragmentation theory of the formation of the large scale structure of the universe is explained and contrasted with the continuous clustering theory. ... Use: Authors Title Abstract Text Text Query with Keywords Return: Query Results Query Form Database: Astronomy Instrumentation Physics and Geophysics ABSTRACT QUERY USER FEEDBACK HELP ...

... 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. ...

. Cosmology . Very Early Universe . Cosmic Microwave Background Anisotropy . Dark Matter Models . Large Scale Structure . High Energy Astrophysics . Active Galactic Nuclei . Astrophysics of Compact Objects . Accretion Disks . Scientific Staff:

... Subject and Problems of Stellar Astronomy. ... Plane of Galaxy, Methods of Its Location Determination. ... Stars Distances. ... Other Methods of Stars Distances Determination. ... Tangential Velocities, Their Determination by Self-Motions. ... Determination of Solar Apex and Spatial Velocity by Radial and Spatial Velocities of Stars. ... Features of Orientation and Parameters of Peculiar Stellar Velocities Ellipsoid. ... General and Selective Light Absorption in Galaxy. ... Darc Clouds in Galaxy. ...

Electronic access is now available for all ASP Conference Series Volumes. View the current list available on this page or browse the e-Book Access site . You may receive access with the purchase of a hard copy volume from the AstroShop , with an institutional subscription , or e-only purchases of books or articles on the e-Book Access site. ... Vol 1-218 . ... Vol 219+ . ... Purchase the printed volume, which includes free electronic access. ... Vol. ... Print ISBN: 0-937707-53-8 . ...

... STELLAR DYNAMICS: FROM CLASSIC TO MODERN . ... Sobolev Astronomical Institute, Saint Petersburg State University, Russia . ... The proposed meeting is being organized by the St.Petersburg State University, assisted by an international Scientific Organizing Committee, and marks the centennial of Professor K.F.Ogorodnikov's birth. ... The conference will be organized by the Sobolev Astronomical Institute of St.Petersburg State University in the building of the Faculty of Mathematics and Mechanics. ...

Clusters of galaxies are the largest gravitationally bounded structures in the Universe dominated by dark matter. We review the observational appearance and physical models of plasma structures in clusters of galaxies. ... The knowledge of the complex dynamical and feedback processes is necessary to understand the energy and matter balance as well as to constrain the role of the non-thermal components of clusters. ...

... AGES Precursor Observations · Targeted the M74 ( NGC 628) group · Noise falls as t (to 200s) AGES Precursor Observations · Targeted the M74 ( NGC 628) group · Noise falls as t (to 200s) AGES Precursor Observations · Targeted the M74 ( NGC 628) group · Noise falls as t (to 200s) · Detected 5 galaxies in the group KDG 010 dw0137+1540 UGC 1171 AGES Precursor ...

... Galaxy clusters in presence of dark energy: a kinetic approach . ... The external regions of galaxy clusters may be under strong influence of the dark energy, which was discovered by observations of supernovae Ia at redshift z < 1. The presence of the dark energy in the gravitational equilibrium equation, with the Einstein ? ... diagram where equilibrium solutions are not possible. ... Galactic Cluster in the Presence of Dark Energy . ...

... Observing . ... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Chandra weighs most massive galaxy cluster in distant universe . ... Using NASA s Chandra X-ray Observatory, astronomers have made the first determination of the mass and other properties of a young distant galaxy cluster. The Chandra study shows that the galaxy cluster, seen at the comparatively young age of about 800 million years, is the most massive known cluster with that age or younger. ...

... 2001 - present-day Researcher in Theoretical Department of Astro Space Center of Lebedev Physical Institute ot RAS . ... Department Number . ... Astro Space Center . ... arna@lukash.asc.rssi.ru . ... Arkhipova N.A., Komberg B.V., Lukash V.N., Mikheeva E.V., "Population of Cosmic Voids", Astronomy Reports 51, pp 787-796 (2007) . ... Surdin, V.G., Arkhipova, N.A., "Influence of dissipation and dynamical friction on the number of globular clusters in a galaxy", Astronomy Letters, Vol.24, p.343 (1998) ...

... The (very) slow rotation of magnetic Ap stars. ... Magnetic stars in young clusters and associations. ... Magnetic fields in low-mass stars from high-resolution infrared spectroscopy. ... Magnetic field measurements of late B-type starss. ... Measurement of magnetic field of FK Com. ... Magnetic field of white dwarfs. ... The magnetic star evolution project (teleconference). ... Conference-2014 . Program . ... Laboratory for the Stellar Magnetism Study of SAO of RAS . ...

... Запорожский клуб АЛЬТАИР > . Catalogue of 109 new Galactic open clusters, for Cartes du Ciel . ... Cartes du Ciel - Sky Charts . ... Этот каталог является версией части каталога "J/A+A/440/403 109 new Galactic open clusters (Kharchenko+, 2005) ", а именно файла stars.dat, содержащего информацию о 26778 звездах до 14.627m , находящихся в 130 рассеяных скоплениях района Млечного Пути (Galactic Open Cluster). ... We present a list of 130 Galactic Open Clusters, found in the All-Sky . ...

THE SUBSYSTEMS OF THE MILKY WAY HALO. ... A catalogue of homogeneous fundamental astrophysical parameters for 145 globular clusters is composed on the base of the data of compilative catalogue by Harris (1997) and from another literature. ... In addition, it has large rotation velocity ( V rot =77?33 km/s), appreciable radial and vertical metallicity gradients equal by value, and has the oldest average age (subsystem of the old halo). ... Characteristic parameter of globular cluster subsystems. ...

ABSOLUTE PROPER MOTIONS OF 331 OPEN CLUSTERS . ... The proper motions of stars in the fields of 331 open clusters were taken from Four-Million Star Catalog (4M-catalog) of positions and proper motions (Volchkov et al. ... The absolute proper motions for 21 young open clusters have been derived by comparison of precise relative proper motions of individual stars and their corresponding absolute proper motions. ... Sign of proper motions in RA . ... 0.0001 arcsec/yr . ... rms error in RA proper motion . ...

Astronotes Armagh Planetarium's Stellar Blog! ... Comets and Asteroids . ... Image credit:ESO/J.Emerson/VISTA. ... However others are less pessimistic and it has even been claimed that the mysterious ?Wow! signal? received in 1977 originated from the direction M55.б  Sadly, this still unexplained pulse of radio energy originated from a location rather to the northwest of M55 so I doubt if the source was this cluster (if indeed the signal was genuinely of extraterrestrial origin). ... Mysterious Wow! ...