... Tonight's Sky . ... The Magazine . News . Observing . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Open cluster NGC 2818, spiral galaxy NGC 2964, and spiral galaxy NGC 2976 . ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...

... 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]. ...

... 2001 March 11 . NGC 1818: A Young Globular Cluster . ... Explanation: Globular clusters once ruled the Milky Way . Back in the old days , back when our Galaxy first formed, perhaps thousands of globular clusters roamed our Galaxy . ... There are few, if any, young globular clusters in our Milky Way Galaxy because conditions are not ripe for more to form. ... Pictured above is a "young" globular cluster residing there: NGC 1818 . ... About APOD | ...

... About ATMoB . ... The Observing Committee is starting an Observing Awards Program to promote observing among the membership of the Amateur Telescope Makers of Boston. ... Participant must be a current member of the Amateur Telescope Makers of Boston . ... To qualify for your Observing Award Certificate, turn in your worksheet and drawings to an ATMoB Observing Committee member or observing@atmob.org . ... This Excel sheet has useful macros. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

... Compact Binaries . ... Globular Clusters . ... Ultra-Compact binaries in globular clusters . ... It is known that UC X-ray binaries are more abundant in globular clusters compared to that found in Galactic fields (eg van der Sluys, Verbunt \ Pols 2005 and references therein). On the other hand no AM CVn systems have been found in globular clusters, while 20 are known in the Galactic field (for a review of AM CVn systems see Nelemans 2005). ...

Alexey Rastorguev's links to DataBases and Catalogs: . ... Open Clusters and Galactic Structure База данных и каталог рассеянных скоплений Галактики . ... USNO: Astronomical Applications Каталоги и базы данных - проекты Морской Обсерватории США . ... HST Science Data Archive Архив данных HST . CFHT Data Archive Архив данных CFHT . ... USNO Recommended Star Catalogs (Zacharias N. et al.) ... USNO Star Catalogs Каталоги USNO . ... USNO-B1.0 Catalog Астрометрический каталог USNO-B1.0 . ...

... A bibliographic database will be constructed with the purpose to be a general tool for searching references for galaxy clusters. ... Clusters of galaxies are the largest gravitationally bound systems in the Universe. ... It is reasonable to test the basic concepts which will be incorporated in the database using A/ACO clusters of galaxies (Abell 1958; Abell, Corwin, & Olowin 1989). ... The first catalog of clusters of galaxies was published by Abell (1958) for and extended by Abell et al. (1989) for...

... Bad Astronomy . ... Bitesize Astronomy . ... The next step up are true clusters, called open clusters . Open clusters (sometimes misleadingly called "galactic clusters") are groups of stars ranging in size from a few dozen stars up to tens of thousands. ... The youngest is about 1 or 2 million years old, while the oldest is about 6 or 7 billion years, making it just older than our own solar system. ... So by looking at the stars in the cluster we can tell pretty well how old they are. ...

... Ultraluminous X-ray sources (ULXs) are located in external galaxies, their X-ray luminosities (10 39 - 10 41 erg/s) are thousand times greater than those of brightest black holes in the Galaxy. ULXs may be supercritical accretion disks around black holes of stellar masses (~10 Solar masses) like that in SS433, or they may be a hypothetical intermediate-mass black holes (hundreds - thousands Solar masses) with standard accretion disks. ... 2) The ULX progenitors were ejected from the star clusters. ...

Find Similar Abstracts . ... Intergalactic gas in galactic clusters, the microwave background radiation and cosmology . ... The types of information that can be obtained from astrophysical studies of the microwave background in the direction of galactic clusters and from radio observations of clusters are examined. ... 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 ...

... 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. ...

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? ...

Globular Clusters as Dynamical Probes of the Virgo Giant Elliptical M49 T.J. Bridges et al. Anglo-Australian Observatory, Australia We have obtained spectra and velocities for 144 globular clusters in the Virgo giant elliptical M49, and are using these data to study the kinematics, ages and abundances of the globular clusters, and the dynamics, dark matter content, and origin of M49. ... We con rm X-ray evidence for a dark matter halo in M49, nding a M/LB  70 at 50 kpc galactocentric radius. ...

... Over the first 4 years, its X-ray telescopes eROSITA and ART-XC will survey the whole sky with a record sensitivity in the 0.5-10 keV energy band. ... The goal of the second international Spectrum-RG conference is to discuss the different scientific topics addressed by the mission, synergies with surveys at other wavelengths, and requirements to follow-up observations.Contributed talks and poster presentations are invited on the topics related to the SRG science goals. ... Active galactic nuclei . ...

... 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. ...

ADC CATALOG HOLDINGS SHORT TITLE LIST March 29, 2002 (adapted from ftp://adc.gsfc.nasa.gov/pub/adc/archives/catalogs/key) Category 1: Astrometric and Positional Data - March 29, 2002 1090 Positions of 502 Stars in Pleiades Region (Eichhorn+ 1970) 1107A Washington Cat Visual Double Stars 1984.0 (Worley, Douglass 1984) 1131A SAO Star ...

Title: A New Model of the Gravitational Lens 0957+561 and a Limit on the Hubble Constant . Authors: Norman A. Grogin , Ramesh Narayan (Harvard Univ.) ... Title: ROSAT/PSPC observation of the distant cluster CL0939+472 . ... Title: Interaction in the Bimodal Galaxy Cluster A3528 . ... Title: Cosmological Implications of Galaxy Cluster Evolution . ... Title: Galaxy Cluster Virial Masses and Omega . ... Matches 201 to 222 from a total of 222 matches for the search pattern galaxy cluster . ...

Central Bodies Masses of Selected Globular Clusters N.A.Shakht, A.A.Kiselev, Yu.N.Gnedin and E.A.Grosheva. The Main Astronomical (Pulkovo) Observatory RAS 47 Tuc ­NGC 104 RA 00 24 .1 Dec -72° 04 .9 Size = 30.9 mvis + 4. 0 m D from = 12,1 kpc, h m Cen - NGC 5139 NGC 6397 (Ara) RA 17 h40.m7 Dec -53o 40'.4 Size = 31',0 mvis + 5,3m D from =2.3 kpc RA 13h 26m .8 Dec -47° 28 6 Size = 36.3 m vis +3. 7 m D from =15.8 ±1.1 kpc, 12109 years, Age: 10109 years, (13.4 ± 0.8)109 years. ...

... 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 . ...

. of Lomonosov Moscow State University, . Russia . GCVS Research Group . Catalogues of Variable Stars . Future Prospects of Variable-Star Catalogues . B.V. Kukarkin Centenary Conference: Variable Stars, the Galactic Halo and Galaxy formation (VS-Halo) . What's new . Recent publications . Digitization of Moscow Plate Archive . The "Peremennye Zvezdy" (Variable Stars) journal . Send questions and comments to Olga Durlevich .