... Arp 188 and the Tadpole s Tidal Tail . ... Credit: ACS Science Engineering Team , NASA Explanation: In this stunning vista recorded with the Hubble Space Telescope's new advanced camera , distant galaxies form a dramatic backdrop for disrupted spiral galaxy Arp 188, the Tadpole Galaxy. ... Following its terrestrial namesake , the Tadpole Galaxy will likely loose its tail as it grows older, the tail's star clusters forming smaller satellites of the large spiral galaxy. ... NASA Official: Jay Norris. ...

home publications > mercury . ... Big Clusters, Tiny Galaxies . ... Astronomers struggle to understand why giant star clusters form in the tiniest of galaxies . ... These clusters are probably young versions of globular clusters, but they are commonly called super star clusters. Seven dwarf galaxies within 16 million light-years have formed super star clusters, with one of these galaxies, NGC 1569, possessing two young clusters. ... Super star clusters have a lot to tell us about star formation. ...

... 2001 November 3 . Bright Stars, Dim Galaxy . Credit: L. Drissen, J. Roy and C. Robert ( Universite Laval ), Y. Dutil ( CFHT ), NASA . Explanation: These two clusters of bright, newly formed stars surrounded by a glowing nebula lie 10 million light-years away in the dim, irregular galaxy cataloged as NGC 2366. ... A comparison with ground based images indicates that in three years this star's brightness increased by about 40 times making it currently the brightest star in this dim galaxy . ...

GALAXIES cenA .tiff 40 Bright Radio Galaxy M31.tiff Nikon Andromeda Galaxy (note HII regions in spiral arms) ngc6744.tiff 40 NGC 6744 a face-on spiral clouds_20d.tiff H'blad The Magellanic Clouds our nearest neighbours Lmc_7.tiff Nikon The Large Magellanic Clouds Lmc_zoom.tiff Nikon Detail of previous image smc_7.tiff Nikon The Small Magellanic Clouds smc-zoom.tiff Nikon Detail of previous image 30dor_40_BVR.tiff 40 The 30 Dor ... B [OIII] Halpha trifid.tiff 40" The Trifid Nebula. ...

... STScI-PRC00-25 A DYING STAR IN GLOBULAR CLUSTER M15 The globular cluster Messier 15 is shown in this color image obtained with the NASA Hubble Space Telescope's Wide Field Planetary Camera 2 (WFPC2). ... Known as Kuestner 648, this was the first planetary nebula to be identified in a globular cluster. ... At the present time, the most massive stars remaining in M15 have about 80 percent of the mass of our Sun, a fact that makes the existence of a planetary nebula like K 648 something of a mystery. ...

Photon Scattering: Basic Principle of Photon Scattering . Audio Narration is available . No Scattering: Photon Source and Detector . ... For optical photons, scattering goes as wavelength to the -4 power. In the case of blue photons compared to red photons, this means that blue photons are about 10 times more likely to get scattered than red photons. ... Watch the blue photons scatter away from the detector . ... Interstellar dust make stars appear redder than they really are . ...

... Kalirai and Harvey Richer of the University of British Columbia led the study, which began as an investigation of a globular star cluster in the Milky Way galaxy known as NGC 6397. ... Within the population of stars and galaxies behind NGC 6397, the Hubble image revealed a large elliptical galaxy that contains several hundred globular clusters. ... In fact, a single giant star in NGC 6397 appears 10 million times brighter than one of the distant globular clusters. ...

This image from the NASA/ESA Hubble Space Telescope shows NGC 6388, a dynamically middle-aged globular cluster in the Milky Way. ... A new study using Hubble data has discovered that globular clusters of the same age can have dramatically different distributions of blue straggler stars within them, suggesting that clusters can age at substantially different rates. Credit: NASA/ESA/F. Ferraro (University of Bologna) ...

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! ...

... STScI-PRC95-45a CRUCIBLE OF CREATION: PANORAMIC HUBBLE MOSAIC ZOOMS IN ON MAELSTROM OF STAR BIRTH This spectacular color panorama of the center the Orion nebula is one of the largest pictures ever assembled from individual images taken with NASA's Hubble Space Telescope. ... Though this 2.5 light-years wide view is still a small portion of the entire nebula, it includes almost all of the light from the bright glowing clouds of gas and a star cluster associated with the nebula. ...

... ESO, the European Southern Observatory . ... Survey Telescopes . ... Galaxies . Galaxy Clusters . ... ESO 3.6-metre telescope . ... This spectacular view from the NASA/ESA Hubble Space Telescope shows the rich galaxy cluster Abell 1689. ... One such object, A1689-zD1, appears in this picture тАФ although it is still so faint that it is barely seen. New observations with ALMA and ESOтАЩs VLT have revealed that A1689-zD1€аis a dusty galaxy seen when the Universe was just 700 million years old. ...

... This paper ( Burke et al. 2003 ) describes the creation of one such catalogue - the Southern Serendipitous High-redshift Archival ROSAT Cluster (SHARC) survey - which covers an area of 17.7 deg 2 and consists of 32 clusters with redshifts between 0.05 and 0.7 and X-ray luminosities between 7 x 10 42 and 4 x 10 44 erg/s: the high-redshift subsample contains 16 clusters with = 0.3 and X-ray luminosities greater than 2 x 10 43 erg/s (luminosities are quoted for the 0.5 - 2.0 keV energy band). ... 1997 ...

... 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. ...

... Gravitational microlensing of giant luminous arcs: . a test for compact dark matter in clusters of galaxies . ... This paper discusses a new test for the detection of stellar mass compact dark matter in galaxy clusters by observing its gravitational lensing influence on the surface brightness of giant luminous arcs. ... With the advent of the Next Generation Space Telescope, cluster dark matter in the form of compact objects will induce a ubiquitous `shimmering' of the giant arcs. ... Giant Arcs . ...

... 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. ...

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 . ...

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. ...

... 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. ...

Our publications in 1997 year Izotov, Yu. I.; Thuan, T. X.; Lipovetsky, V. A. Dwarf Galaxies: Probes for Galaxy Formation and Evolution, Joint Discussion 2, 21 August 1997, Kyoto, Japan. Izotov, Yuri I.; Thuan, Trinh X.; Lipovetsky, Valentin A. Astrophysical Journal Supplement, 01 1997, v.108, p.1 . ... Pustil'nik, S. A.; Lipovetsky, V. A.; Izotov, Y. I.; Brinks, E.; Thuan, T. X.; Knyazev, A. Y.; Neizvestnyi, S. I.; Ugryumov, A. V. Pis'ma Astron. ... 74, August 1997, p. 536 . ...

... In the past used to check pn/ MOS cross calibration Example of old vs new pn/ mos Residuals in the form of ratio data / model for PN data on MOS best fitting model Example of old vs new pn/ mos Residuals in the form of ratio data / model for PN data on MOS best fitting model ACIS S3 vs EPIC pn · · Same thing, only now we compare Chandra ACIS S3 with ... Flux cross-cal · · The new HRMA calibration impacts on the ACIS/EPIC flux cross calibration. ...