... NGC 1999: Reflection Nebula In Orion . ... M13 is one of the most prominent and best known globular clusters. ... In 46 BC, Julius Caesar, pictured above in a self-decreed minted coin, created a calendar system that added one leap day every four years. The Sombrero Galaxy from VLT . ... Visible predominantly from Earth's Southern Hemisphere, the LMC is the second closest galaxy, neighbor to the Small Magellanic Cloud, and one of eleven known dwarf galaxies that orbit our Milky Way Galaxy. ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2003 December 27 . The Pleiades Star Cluster . ... Explanation: Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city . ... About APOD | ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ...

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! ...

... Press Release Images . Individual Images . ... The right-hand image shows Hubble's close-up view of the galaxy's core, taken in December 1995 by the Wide Field and Planetary Camera 2. The bluish-purple clumps that form the ring are the clusters of infant stars. Two dark, wispy lanes of dust and a pair of blue spiral arms are just outside the star-forming ring. ... The gas is trapped inside the ring through the stars' gravitational attraction. ... Amazing Space | ...

. F IGURE . 2. The distribution of globular clusters projected onto the XY [(a) and (c)] and YZ [(b) and (d)] planes for metal-rich clusters of the thick disk with [Fe/H] -1.0 [(a) and (b)] and metal-poor clusters of the halo [(c) and (d)]. The closed curves are upper envelopes drawn by eye. Clusters lying far from the central concentrations in the diagrams are outlined and their numbers indicated. discussion in the text | previous figure | next figure .

... 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....

... Science User Portal . ... ESO, the European Southern Observatory . ... Travel and Contacts . Travel to ESO Headquarters . ... ESO . ... Survey Telescopes . ... Galaxy Clusters . ... Star Clusters . ... Stars@ESO . ... ESO Science Newsletter . ... View shopping cart . ... This close-up video pan sequence gives a detailed look at a new image of the star cluster Messier 47 taken using the Wide Field Imager camera, installed on the MPG/ESO 2.2-metre telescope at ESOтАЩs La Silla Observatory in Chile. ...

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. ...

... IYA 2009 FREE TO ENTER COMPETITION: deadline extended . Due to a late surge of interest, the closing date for this competition has been given one FINAL extension - . to 15 December 2009. ... Thursday, 3 December 2009 16:10 . International Year of Astronomy, Ireland National Node . ...

... 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. ...

... 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. ...

... 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. ...

... This image shows a 7th magnitude star cluster, it's reflection nebula, an extended diffuse nebula and Barnard Dark Nebulae. The bright star at the top is omicron Persei (Atik). The cluster next to Atik is a star forming region with as many as 300 stars ranging from the brightest at B5 to low mass brown dwarfs. ... The obscuring dark areas are the Barnard Dark Nebulae 1 through 4. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

... 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. ...

... Since moonshine is really reflected sunlight, the full Moon is on the average slightly brighter in mid-winter, when Earth is closest to the Sun. In addition, the distance of the full Moon also varies, due to the ellipticity ("eccentricity") of the Moon's orbit. On 22 December, 1999, the two effects combined to produce the brightest full Moon of the century. ... This year will be the first full moon to occur on the winter solstice, Dec. 22nd, commonly called the first day of winter. ...

... 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. ...

... MAO main . ... The DRAGON globular cluster simulations: a million stars, black holes and gravitational waves . ... simulations of globular clusters with a million stars on the high-performance . ... of stars in globular clusters at unprecedented detail but also shed light into . the dark world of black holes. ... clusters of single and binary black holes. ... of a globular cluster. www.mpa-garching.mpg.de/328833/hl201603 . ... MAO/NASU, 27 Akademika Zabolotnoho St. 03680 Kyiv, Ukraine . ...

... Ultraluminous X-ray sources (ULXs) are located in external galaxies, their X-ray luminosities (10 39 - 10 41 erg/s) are thousand times greater than those of brightest black holes in the Galaxy. ULXs may be supercritical accretion disks around black holes of stellar masses (~10 Solar masses) like that in SS433, or they may be a hypothetical intermediate-mass black holes (hundreds - thousands Solar masses) with standard accretion disks. ... 2) The ULX progenitors were ejected from the star clusters. ...

... How to calibrate the energy scale for higher energies of future gratings? Difficult to find astronomical targets with well defined lines. ... Source Energy Flux keV HZ 43 0.2 Bright Sirius B 0.2 HZ43 /10 RXJ1856 1 Faint Simplicity Var WD WD No No No No Yes Yes Extend Lines Point Point Point 1' Point Point Point No Point Point Yes No Yes Yes Yes Yes Point Point , jet Point Cont Cont Cont Cont Lines Cont Lines Lines Lines ...

... The Pleiades star cluster, also known as the Seven Sisters and Messier 45, is a conspicuous object in the night sky with a prominent place in ancient mythology . ... The stars in the Pleiades are thought to have formed together around 100 million years ago, making them 1/50th the age of our sun, and they lie some 130 parsecs (425 light years ) away. ... Data for these stars are listed in a table below. ... Yes . ... WEBDA Pleiades cluster data . ... M45: The Pleiades Star Cluster (2007 November 18) ...