... M4: The Closest Known Globular Cluster . ... 23.05.2000 . ... Credit Copyright: T2KA , KPNO 0.9-m Telescope , NOAO , AURA , NSF Explanation: M4 is a globular cluster visible in dark skies about one degree west of the bright star Antares in the constellation Scorpius . M4 is perhaps the closest globular cluster at 7000 light years , meaning that we see M4 only as it was 7000 years ago, near the dawn of recorded human history . ... Publications with keywords: cluster - M 4 - globular cluster . ...

Today's APOD | ... Editor's choices for the most educational Astronomy Pictures of the Day about open clusters: . APOD: 2006 January 9 - M45: The Pleiades Star Cluster . ... The Pleiades contains over 3000 stars, is about 400 light years away, and only 13 light years across. ... Two types of star clusters are visible in our Milky Way Galaxy : open clusters and globular clusters . ... Aged 80 million years, M47 is a smaller but looser cluster of about 50 stars spanning 10 light-years. ... Index | ...

... 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. ...

... October 18, 1999 . NGC 3603: An Active Star Cluster . ... Explanation: NGC 3603 is home to a massive star cluster, thick dust pillars, and a star about to explode . The central open cluster contains about 2000 bright stars, each of which is much brighter and more massive than our Sun . ... These stars are less massive than our Sun, demonstrating that great numbers of low-mass stars also form in active starburst regions . ... About APOD > . ...

XMM-Newton observation of the core of the massive cluster Cyg OB2 located in the constellation Cygnus, 4,700 light-years from Earth. The cluster contains massive O-type stars that shine brightly in X-rays. Cyg OB2 #9 is seen as the bright star just below the central star, and in 2008 was determined to be a binary system. ... Hundreds of lower mass stars also fill the field of view, which spans nearly 22 x 16 arcminutes. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . See also images taken on November 22nd . Image taken by Andy McCrea who says, . To me the comet appears yellowish and it has gone from star-like to a . ... More images from Andy McCrea here . ... The true explanation is that a very faint comet, known as periodic comet Holmes, produced a massive outburst of material and became a million times brighter than it was just a day earlier. ... More images from Andy McCrea . ...

... The sharp vision of Hubble's Advanced Camera for Surveys uncovered the speedy white dwarfs in the ancient globular star cluster NGC 6397, a dense swarm of hundreds of thousands of stars. ... The distribution of young white dwarfs is the exact opposite of what we expected," said astronomer Harvey Richer of the University of British Columbia in Vancouver. ... The idea that young white dwarfs are born with a kick was suggested 30 years ago to explain why there were so few of them in open star clusters....

Stellar Clusters are very useful laboratories for empirically studying stellar evolution. ... All cluster stars are at the same distance . All cluster stars have the same physical age . ... CM diagram Young Cluster In this case we see the Main Sequence fully represented. The blue dots represent massive stars with short main sequence lifetimes. ... Thus, identifying the most massive star which is still on the main sequence is an effective means of determining the age of a stellar cluster. ...

... self-absorption - the absorption of light shining on an object by a process similar to that which produced the light originally; if a cloud emits less light than it absorbs from other clouds behind it, this net loss of light, termed self-absorption , causes the foreground cloud to appear darker than the background field (the term is from spectroscopy, where small absorption dips sometimes occur in larger emission lines, making the latter look as if it is absorbing part of itself) . ... HISA Main ...

... A few weeks ago, around a galaxy far, far away, a new type of mysterious БЂњdarkБЂќ star cluster was spotted. Our Galaxy, the Milky Way, is surrounded by about 150 groups of stars, which are called globular clusters. ... A galaxy called Centaurus A (sen-TOR-us Ay) is surrounded by thousands of globular clusters. ... These globular clusters aren't the only dark object in Centaurus A, at the centre of this galaxy lies a black hole that is 55 million times more massive than our Sun! ...

... 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. ...

... 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. ...

... BLUE STRAGGLER STARS are unusually hot and bright stars found in the cores of ancient star clusters known as globulars. ... BACKGROUND (from wikipedia): Blue straggler stars are stars in open or globular clusters that are hotter and bluer than other cluster stars having the same luminosity. ... There is evidence in favor of this view, notably that blue straggler stars appear to be much more common in dense regions of clusters, especially in the cores of globular clusters. ...

... Find the three stars of his belt and follow the line they make up the sky and you will meet Aldebaran, the brightest star in Orion?s neighbour, Taurus the Bull . ... A K5 III red giant about 350 times as luminous as our Sun, it appears as a red-orange magnitude 0.9 object in our sky. ... The name Aldebaran is derived from the Arabic for тАШthe FollowerтАЩ as the ancient Muslim astronomers saw it as trailing behind the Pleiades star cluster across the sky. ... Posted April 2, 2014 at 8:03 PM . ...

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. ...

... Centaurus A : 15,000,000 light years away, in the constellation Centaurus, the closest AG to Earth . ... Astronomers think that the reason for the unusual shape of this galaxy is because hundreds of millions of years ago two galaxies, one dusty spiral and one bright ellipictal, collided causing a massive black hole in the middle and bright emmision of light. ... Andromeda galaxy: 2.8 million light years away, closest spiral galaxy to earth, farthest object one can see without a telescope. ...

... Australia Telescope Compact Array . ... Compact Stellar Systems in the Fornax Cluster: Super-massive Star Clusters or Extremely Compact Dwarf Galaxies? ... We suggest that these objects are either super-massive star clusters (intra-cluster globular clusters or tidally stripped nuclei of dwarf galaxies) or a new type of low-luminosity compact elliptical dwarf (``M32-type'') galaxy. ... Keywords: galaxies: star clusters -- galaxies: dwarf -- galaxies: formation . ... Properties of the compact objects ...

... Today this year's largest group of sunspots will cross the Sun's central meridian. ... The next day, the number of spots in the group reached five, and the day after, on June 2nd, it was possible to count thirteen sunspots on solar disk, which had been clear prior to this. ... This year's two most powerful active areas, which passed across the solar disk at the beginning of May, 2009, are set to appear in the Sun's eastern sector in two days, on June 6th. ...

Results from 6m telescope observations of globular clusters in dwarf galaxies Sharina M. We consider properties of globular clusters in dwarf galaxies observed with the multi-slit unit of the SCORPIO spectrograph at the SAO 6m telescope. ... Studying GCs in dwarf galaxies at the faintest end of the galaxy luminosity function provides valuable information for a better understanding of galaxy evolution and evolutionary connection between globular clusters and nuclei of galaxies. ...

The Sun is our nearest star and the source of energy for life on Earth. ... For centuries astronomers wondered whether they were clouds floating in the Sun's atmosphere, but we now know that they really are huge regions of magnetic field, about as intense as the field at the poles of an iron magnet. ... Such abrupt events were named solar flares , and what made them especially interesting was that occasionally, after a prominent flare, a magnetic storm would erupt on Earth. ...