... While imaging the cluster of galaxies Abell 370, astronomers had noted an unusual arc to the right of many cluster galaxies. ... In the mid-1980s, however, better images allowed astronomers to identify the arc as a prototype of a new kind of astrophysical phenomenon -- the gravitational lens effect of entire cluster of galaxies on background galaxies. ... In mid-July, astronomers used the just-upgraded Hubble Space Telescope to image Abell 370 and its gravitational lens images in unprecedented...

... 2007 March 5 . Illusion and Evolution in Galaxy Cluster Abell 2667 . ... Explanation: What's happening to the galaxies of cluster Abell 2667? ... To start, most of the yellowish objects in the above image from the Hubble Space Telescope are galactic members of a massive cluster of galaxies known as Abell 2667 . ... Light from this galaxy is gravitationally lensed by Abell 2667, appearing much like a distant person would appear through a wine glass. ... About APOD | ...

... May 3, 1997 . Giant Cluster Bends, Breaks Galaxy Images . ... Explanation : What are those strange blue objects? Many are images of a single, unusual, beaded, blue, ring-like galaxy which just happens to line-up behind a giant cluster of galaxies. ... The distinctive shape of this background galaxy -- which is probably just forming -- has allowed astronomers to deduce that it has separate images at 4, 8, 9 and 10 o'clock, from the center of the cluster. ... About APOD > . ...

M1 image More About M1 Nice Color Picture . ... M16 image More About M16 HST image . ... M31 image More About M31 Nice Color Picture . ... M42 image ; M43 image More About M42/43 Nice Color CCD Picture . M51 image More About M51 Color Image of M51 M51 Supernova . M57 image More About M57 Nice Color CCD Picture Very Deep M57 Image . ... M81 image More About M81 M81 Supernova Ultraviolet Image of M81 More about Ultraviolet Imaging . M82 image More About M82 M82 False Color M82 True Color . ...

... Bad Astronomy . ... Bitesize Astronomy . ... Last week's Snack talked about how black holes can affect the environment around them in such a way as to be very bright . ... It's a common misconception that black holes always have matter swirling into them. ... As this matter gets closer and closer to the black hole it piles up and a large, fairly flat disk forms. This is called the accretion disk , because matter from this disk accretes (that is, falls in) on the black hole. ... 2008 Phil Plait. ...

Astronotes Armagh Planetarium's Stellar Blog! ... Stars . ... Space Flight . ... September . ... Posted on November 26, 2010 | 6 Comments Cepheid variables are massive, pulsating stars, valued by astronomers for the precise link between their brightness and steady pulsation. ... Continue Reading.. ... Posted on October 6, 2010 | ... Posted on September 27, 2010 | No Comments Here?s how rainbows are made. ... No Comments At first glance Gliese 710 is not a very distinguished star. ...

Astronomy.com - A star cluster hides star clusters 4/2/08 11:35 AM News A star cluster hides star clusters Deep Hubble images of NGC 6397 reveal the most distant star clusters ever seen. Francis Reddy January 10, 2007 W hile exploring deep Hubble Space Telescope images of a globular star cluster called NGC 6397, astronomers stumbled on a distant background galaxy harboring hundreds of similar clusters. Each is so distant, it appears only as a faint point of light, even to Hubble's keen eye. ...

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 . ...

... Confirm Dark Galaxy Existence . ... New evidence from NASA's Hubble Space Telescope and the Westerbork Synthesis Radio Telescope in the Netherlands has been used to rule out all but one of the ideas put forward to explain the existence of VIRGOHI 21, an intergalactic gas cloud 50 million light-years from the Earth. ... Are there more such dark galaxies out there? ... Credit: R. Minchin / Arecibo Observatory / Cardiff University / Isaac Newton Telescope / Westerbork Synthesis Radio Telescope . ...

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 . ...

... Primordial theory review : Dick Bond . Defects and the CMB review : Andy Albrecht . ... Gravitational wave contribution to CMB anisotropies : V.B. Lukash and E.V. Mikheeva . C_l from cosmic strings : Lloyd Knox . Some aspects of CMB anisotropies induced from topological defects : Mairi Sakellariadou . ... CMB anisotropies from scaling sources : Ruth Durrer . ... SZ observations I : Sarah Church . ... Holes in the microwave sky? ... Detecting cosmic strings in the CMB : James Robinson . ...

... galaxies . ... Another violent galaxy cluster collision discovered . The so-called Musket Ball Cluster is the sixth such merging cluster with separation between normal matter and dark matter that astronomers have found. ... A system of colliding galaxy clusters, nicknamed the Musket Ball Cluster, has been discovered. ... The newly discovered system has been nicknamed the т??Musket Ball Clusterт?? because the cluster collision is older and slower than the Bullet Cluster. ... Discover | ...

... The search for distant objects which can be both galaxies and quasars is one of the most important problems of observational astrphysics, because it allows one to determine cosmological parameters connected with the time of appearence and evolution of stellar systems, large scale structure of the Universe. ... Radio galaxies are important objects to be studied because they are sources of infrared-optical-ultraviolet continuum, emission lines and continual radio emission. ...

In 2001, Westerbork observations of the disturbed galaxy named VV-29 (alias Arp-188, UGC-10214) showed that there is second smaller galaxy (named VV-29c) that appears behind the western side of the main body of the distorted galaxy. ... The galaxy was featured as the May 2, 2002 Astronomy Picture of the Day . ... When VV-29 had its 15 minutes of fame in May 2002, it appeared under the name "The Tadpole Galaxy," but based on the images above, we will always think of it as "The CHAINSAW"! ...

In autumn 1994, two groups of astronomers announced that they had discovered Cepheid variable stars in a distant cluster of galaxies. ... As the term suggests, variable stars change in brightness over time. ... Variable stars are an ideal way to get high-school students doing real science, with real data, from the real sky. ... a sky chart to find the stars . ... Students can use the nearby stars to estimate the magnitude of Delta. ... Locate the star Delta in Cepheus and estimate its brightness . ...

... Science Activities > PhD Thesis Topics offered by ESO Faculty Members > Thesis Topic: Dynamical models of multiple globular cluster populations around massive galaxies . ... Different techniques have been devised to separate multiple GC populations and perform dynamical analyses. ... Within this project, the PhD candidate will examine mock models of multiple GC populations around massive galaxies, devising `blinded' functional tests and comparing the possible sources of bias in different techniques....

This animation shows a galaxy cluster with two mass concentrations (the pink shading indicates the projected mass density) lensing a background field of faint blue galaxies. ... Inside the Einstein ring radius one has radial arcs, and right in the center of the cluster there are demagnified images. The highest magnifications occur at the Einstein ring radius, giving the large tangential arcs. ... Abell 2218 and CL2244-02 are clusters with tangential arcs. ... Tutorial : Part 1 | Part 2 | ...

... 1) A new bright galaxy of the Local Group VV124 (UGC4879) is found. ... Kopylov A.I., Tikhonov N.A., Fabrika S.N., Drozdovsky I.O., Valeev A.F., MNRAS Lett, V. 387, Issue 1, L45, 2008. ... For systems of galaxies in the regions of the Hercules and Leo superclusters the dwarf-to-giant ratio of galaxies in the r-band is evaluated, and it is found that this ratio increases with increasing X-ray luminosity at log L X > 43.5 erg/s. Kopylova F.G., Kopylov A.I., Ast. ... Kopylova F.G., Kopylov A.I., Ast. ...

... Eventually galaxies came into being. ... These would form a halo around the galaxy with individual clusters constantly plunging in and out in memory of the original collapse. ... In 1929, five years after he had determined galactic distances, Hubble discovered that the red shifts of galaxies were proportional to their distances. ... However we know the universe does not expand freely and the mutual gravitational attraction of all matter pulls on retreating galaxies and restrains their dispersal. ...

Next: Critical Frequencies and Gravitational Previous: Extragalactic Gravitational Wave Background . The number of binaries per frequency decade per solid angle from a separate stellar system (galaxy or cluster of galaxies) is . ... For example, for the Andromeda galaxy M31 ( rad, ) one gets . ... If the angular size of the galaxy is less than the angular resolution of the detector, the critical frequency is independent of the angular resolution, . ...