... Each day we feature a different image or photograph of our fascinating universe, along with a brief explanation written by a professional astronomer. January 14, 1996 . A Distant Cluster of Galaxies . ... Explanation: Every bright object in this 1994 photograph by the Hubble Space Telescope is a galaxy . ... Photos like this indicate that clusters in the past contained a higher fraction of spirals than do nearby clusters , which are usually dominated by elliptical galaxies . ... About APOD | ...

... A big bright star near the center of the red region appears white hot and emits light so energetic . A Distant Cluster of Galaxies . ... In this 1994 Hubble Space Telescope photograph, every bright object is a galaxy. Oddly - most of them are spiral galaxies. This rich cluster of galaxies, named CL 0939+4713, is almost half way across the visible universe. ... In this dramatic picture, spiral galaxy NGC 5091 appears in the foreground. ... Can you see through the spiral galaxy? ...

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 . ...

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... 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 > . ...

... 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. ...

... 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. ...

... 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. ...

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 . ...

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 . ...

... Tonight's Sky . ... Sky this Month . ... Star Atlas . ... stars . ... The Sky This Week: April 1 - 10 . ... Observing springtime deep-sky objects with a large telescope . ... Why do some stars appear to flash a variety of different colors when you look at them through a telescope? ... So, Earthт??s atmosphere will bend some colors from especially bright stars more so than others, which makes the source look like itт??s flashing colors. Get instant access to subscriber content on Astronomy.com! ...

... Galileo was one of the first to study our Milky Way with a telescope in 1610 and he discovered that it was composed of a huge number of faint stars. ... Image Credit: NASA Elliptical Galaxy This image from NASA's Hubble Space Telescope shows a good example of an elliptical galaxy at the centre of a galaxy cluster that is over 450 million light-years away in the direction of the constellation Centaurus. ... Then the Andromeda galaxy was first classed as a galaxy outside of our own Milky Way. ...

... Special Reports Giant space cloud may be powered by black holes 17:57 23 April 2007 NewScientist.com news service David Shiga An enormous cloud of roiling plasma in space may be drawing its energy from black holes, new observations suggest. Such clouds might be sources for the mysterious particles that occasionally crash into Earth's atmosphere at ultra - high speed. ... But higher energy particles in the cloud may be able to escape, he says. ...

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 . ...

Astronomers at Armagh Observatory and Cardiff University have independently discovered new mechanisms by which micro-organisms may have spread throughout the Galaxy. Scientific papers on the topic by Professor Bill Napier at Armagh, and by Dr Max Wallis and Professor Chandra Wickramasinghe at Cardiff University, will appear simultaneously in the Monthly Notices of the Royal Astronomical Society . ... Cardiff scientists Max Wallis and Chandra Wickramasinghe have identified another delivery route. ...

... We present a photometric and spectroscopic study of the unique isolated nearby galaxy KKR25. The isolated dwarf spheroidal (dSph) galaxy KKR25 was discovered by Karachentseva, Karachentsev Richter (1999, A , 135, 221) during the search of dwarf galaxies in the direction of the Local Void. In spite of its isolation KKR 25 has no gas and looks like a normal dwarf spheroidal system. ... This is the first known planetary nebula in a dwarf spheroidal galaxy outside the Local Group. ...

... We have made observations of the Perseus cluster with the Westerbork Telescope at 610 MHz. ... Several newly detected sources are identified with cluster galaxies. ... No evidence is found for the existence of the previously reported ~ 65'x25' cluster halo, 3C 84B. Key words: radio galaxies - clusters - tailed radio sources buoyancy The Perseus Cluster of galaxies is one of the most fascinating systems accessible to extragalactic astronomers. ...

... Dwarf Spheroidal Galaxies and the Formation of the Galactic Halo . ... Annual Report 1998 . ... It might then be possible to use these signatures as an alternative way to assess the fraction of the general galactic halo that has come from the disruption of dSph galaxies. ... Dark Matter in Galaxies . Kormendy* and Freeman have discovered that the properties of the dark matter "halos" that surround galaxies correlate with galaxy luminosity. ... Carina dwarf spheroidal galaxy . ...

... Our Sun is part of a huge wheel-shaped collection of stars. ... Astronomers have long suspected it was a very massive black hole, and that every galaxy had such a central mass, created early in the history of the universe. ... However, unless that object happens to be headed directly at the black hole (a relatively small target) it will just swing around and fly away again, like a comet making a pass at the Sun. The velocity acquired in falling towards the black hole also helps it escape. ...

... 1st Announcement IAU Symposium 312 Star Clusters and Black Holes Across Cosmic Time, Beijing, China, Aug. 25-29, 2014 . ... SUBJECT: 1st Announcement IAU Symposium 312 Star Clusters and Black Holes Across Cosmic Time, Beijing, China, Aug. 25-29, 2014 . ... which will be held in Beijing, P.R. China, from August 25-29, 2014, hosted by Chinese Academy of Sciences . ... China), . ... 1st Announcement IAU Symposium 312 Star Clusters and Black Holes Across Cosmic Time, Beijing, China, Aug. ...