... All the galaxies are divided into 4 groups depending on the environment type; every subsample contains more than 10 galaxies. ... An effect of environments is seen both for the nuclei and for the bulges: if we consider the clusters (Virgo and Ursa Ma jor) and group centers as dense environments and the field and group periphery as sparse environments, then in the dense environments the stellar populations of S0s are in average older by 4­5 Gyr than in the sparse ones. ...

... We have assumed a constant in time star formation rate and the total number of stars in the Galaxy, , to be such that the total mass of the galaxy is ; assuming the Salpeter mass function   , we get . ... This number agrees with a standard estimation of the galactic star formation rate of order of per year. In each run of calculations, we trace the evolution of binaries with initial parameters randomly distributed according to the chosen initial laws. ...

... Dept. for Physics of Stars&Galaxies . ... Using a database view Sloan Digital Sky Survey (SDSS), containing almost a million spectra created 15,000 sample galaxies with active star formation, which is used for various studies and physical state of evolution of galaxies. ... Star clusters of the Galaxy . The project MWSC (Milky Way Star Clusters) directory using 2MASS, which includes nearly 500 million vision to the limit Ks = 15.3, analyzed more than 4,000 cluster-like objects in the galaxy. ...

... 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. ...

An image of the grand design of spiral galaxy M100 obtained with NASA's Hubble Space Telescope resolves individual stars within the majestic spiral arms. ... Hubble has the ability to resolve individual stars in other galaxies and measure accurately the light from very faint stars. This makes space telescope invaluable for identifying a rare class of pulsating stars, called Cepheid Variable stars embedded within M100's spiral arms. ... 617) 495-7062 . Fax: (617) 495-7356 . ...

... Curriculum Vitae Observations and theory of star cluster formation 22) A.K.Dambis and Yu.N.Efremov Journal for History of Astronomy, 31, 115-134, 2000 Dating Ptolemy's star catalogue through proper motions: the Hypparchan epoch 23) B.G.Elmegreen, Yu.N.Efremov, S.Larsen Astrophys. J., 535, 748 - , 2000 A young globular cluster in the galaxy NGC 6946 24) Yu.N.Efremov. ... 28) Yu.N.Efremov. ... The location of star complexes in the Galaxy was studied in papers with E.Alfaro, L.Berdnikov and T.Sitnik. ...

... It is found that the metallisity distribution of disk stars has a gap which subdivide the disk population into two groups. The distribution may be described by the sum of two normal curves which are centered at [Fe/H]=-0.22 and +0.08. The curves can be interpreted as distributions of random errors in metallisity of sample stars. This leads to the conclusion that all stars in each group have actually the same value of [Fe/H]. ... Рассмотрен вопрос о происхождении подсистем Галактики. ...

... Ciel Espace, le magazine qui vous guide toujours plus loin . ... des actualit†йs . ... les plus belles images de l'Univers d†йcrypt†йes pour vous . ... des pages consacr†йes †а la publication de vos photos Mais c'est aussi une vraie communaut†й avec laquelle partager votre passion et nourrir votre curiosit†й. Accueil Les galaxies barr†йes sont moribondes . ... Les galaxies spirales dont une barre d'†йtoiles traverse le centre (dites barr†йes) sont plus vieillissantes que celles d†йnu†йes de barre. ...

... Field of research: Extragalactic astronomy. ... NASA Astrophysics Data System (ADS) Abstract Service . ... CADC Home Page . ... CCD Images of Galaxies . ... RUSSIAN LINKS . ... UA Astronomy Personal Home Page - Bill Keel . ... The Shape of the Rotation Curves of Edge-on Galaxies, by A.V.Zasov and A.V.Khoperskov, 2003. ... A Thickness of Stellar Discs, by A.V.Zasov, and D.V.Bizyaev, 2003 . Minimum Velocity Dispersion in Stable Stellar Disks, by A.V.Khoperskov, A.V.Zasov, and N.V.Tyurina, 2003 . ...

Bizyaev D., "The Argument Against Long Extragagalactic Distance Scale", Astron. ... Soviet Astronomy) 1997. ... Zasov A., Bizyaev D., "An Estimate of the Hubble Constant using a Criterion for Gravitational Stability of Gaseous Discs", Pis'ma v Astron. ... 1996. ... D.Bizyaev, "Types of galaxies", 1996, Zvezdochet, No 11, p.22 (in Russian) . D.Bizyaev, "The Hubble Constant", 1996, Zvezdochet, No 2, p.20 (in Russian) . D.Bizyaev, "Magellanic Clouds", 1995, Zvezdochet, No 6, p.12. (in Russian) . ...

... Tonight's Sky . ... News . Observing . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... galaxies . ... New discovery challenges galaxy-formation theories . ... Further research into the nature of these objects could open new windows into the study of the origin and early evolution of galaxies. ... New theory improves understanding of galaxy formation . ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...

Class 1 Introduction, Background History of Modern Astronomy The Night Sky, Eclipses and the Seasons Kepler's Laws Newtonian Gravity General Relativity Matter and Light Telescopes Class 2 Solar System Characteristics Formation Exosolar Planets Class 3 Stars The Sun Stellar Evolution of Low and High Mass Stars Deaths of Stars Exotic Stars Class 4 Galaxies Galaxy Classification Formation of Galaxies Galactic Evolution ... So far, one planet has been studied by this method. ...

... Our Milky Way galaxy is host to a number of companions. These companions are gravitationally bound to the Milky Way and are stellar systems in their own right. They include a population of about 150 globular clusters (GCs) and some 30 dwarf satellite galaxies (DSGs). ... These DSGs are more extended and diffuse compared to GCs. In fact the larger satellites of the Milky Way (and other galaxies, for that matter) host their own small systems of GCs. ...

... 314, 2004 F. Ochsenbein, M. Al len, and D. Egret, eds. The Kiso Survey for Ultraviolet-excess Galaxies (KUG) N. Miyauchi-Isobe and H. Maehara National Astronomical Observatory, Mitaka, Tokyo 181-8588, Japan K. Naka jima Hitotsubashi University, Kunitachi, Tokyo 186-8601, Japan Abstract. ... Introduction The KUG survey has begun 1984 as a pro ject of selecting ultraviolet(UV)-excess galaxies and compiling a catalog, with the Kiso 105-cm Schmidt telescope, by B. Takase and N. Miyauchi-Isobe. ...

... Stellar Archaeology: New Science with Old Stars . Dr. Anna Frebel . ... This lecture will address a fundamental question of modern astrophysics: the origin of the elements, which is key to understanding the birth and childhood of our own Galaxy at a time when the Universe was still very young itself. ... Please join us for a pre-meeting dinner discussion at Changsho, 1712 Mass Ave, Cambridge, MA at 6:00pm before the meeting. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

... Courtesy of NASA/ESA Observation data (J2000 epoch) Constellation Right ascension Declination Redshift Distance Type Serpens Caput 15h 17m 14.4s[] +21° 35 08[] 12,740±50 km/s[][1] 600±30 Mly (183±8 Mpc)[1] SA0(r) [citation needed ] [a] Apparent dimensions (V) 0.28 в 0.28[] Apparent magnitude (V) 16.0[] Notable features Ring galaxy Other designations PGC 54559,[] PRC D-51[] See also: Galaxy, List of galaxies Hoag's Object is a non-typical galaxy of the type known as a ring galaxy. ...

... Conjunction Over Armagh . ... Comet and Pleiades . ... Pleiades . ... Antares Region . Helix and Cat's Eye Nebulae . Orion Nebula . Lagoon and Eagle Nebulae . Crab Nebula . ... Our Galaxy Core . Andromeda Galaxy . Wide-field and Zoomed-in Galaxies . Interacting Typhoons and Galaxies . Spiral Galaxy M106 . Sombrero Galaxy . Whirlpool Galaxy . Colliding Galaxies . ... й Miruna Popescu, Armagh Observatory ...

Mikhail Medvedev (University of Kansas) HEA- 2007 , IKI, Moscow Missing baryons in inter-cluster gas Afshordi, et al, 2007 , astro-ph/0612700 35% +/- 8% Sample of 260 clusters WMAP SZ 3yr data Compared with 11 simulated clusters Assumed: Universal NFW profile Self-similarity Isothermal gas Possible explanations Observed stellar mass in galaxies: ~ 10% (Lin, et al, ... Simulations indicate that the effect is small (Dolag, et al, 2004) Can account for ~1-2% missing mass at most ...

... Hubble's (1936) "tuning fork" of galaxy morphologies is the basis for modern galaxy classification. (arXiv:1102.0550.v1) Fig. ... Type E+ galaxies are "late" ellipticals, which may include faint extended envelopes typical of large cluster ellipticals, or simple transition types to S0-. (arXiv:1102.0550.v1) Fig. 7-- Examples of barred and nonbarred S0 galaxies of different stages from "early" (S0-), to "intermediate" (S0o ), to "late" (S0+), including the transition stage to spirals, Fig. ...

... Astronomy news . ... NASA's Spitzer Images Out-of-This-World Galaxy . ... It is spiral-shaped like our Milky Way, with long, spindly arms of stars. The "eye" at the center of the galaxy is actually a monstrous black hole surrounded by a ring of stars. In this color-coded infrared view from Spitzer, the area around the invisible black hole is blue and the ring of stars, white. ... The ring around the black hole is bursting with new star formation. ...