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! ...

... Many bright nebulae and star clusters in planet Earth's sky are associated with the name of astronomer Charles Messier, from his famous 18th century catalog. ... NGC 6903: The Butterfly Nebula . ... The Nebula's glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud. Curiosity: Wheels on Mars . ... The Eagle Nebula and the Swan Nebula span this broad starscape, a telescopic view of the Sagittarius spiral arm toward the center of our Milky Way galaxy. ...

... September 21, 1999 . The Quintuplet Star Cluster . ... Explanation: Bright clusters of stars form and disperse near the center of our Galaxy . ... The Quintuplet Cluster is located within 100 light-years of the Galactic center , and is home to the brightest star yet cataloged in our Galaxy: the Pistol Star . ... The young Quintuplet Cluster is one of the most massive open clusters yet discovered, but still much less massive than the ancient globular clusters that orbit in the distant halo. ...

... Most stars form in clusters, so the simple picture of star formation needs to incorporate the impact that young stars have on their environments, and each other. One region we study is NGC 1333, shown to the left as seen by the Spitzer Space Telescope. This is a тАЬproto-typicalтАЭ star-forming region located тАЬonlyтАЭ 1000 light years away in the direction of the constellation Perseus. ... Copyright 2015 Adele Plunkett. ...

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. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . Portrait of Sir William Herschel (1738-1822) Royal Astronomical Society . Probably the most famous astronomer of the 18th century, Sir William Herschel discovered, in addition to the planet Uranus, many new nebulae, clusters of stars and binary stars. ... Other Herschel Family Portraits . Mirror by Herschel . Return to A Short History of Armagh Observatory . Last Revised: 2009 November 23rd . ...

... 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. ...

... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Astronomy for Kids . ... Astronomy 101 . ... Astronomy Foundation . ... Do globular clusters form in a galaxy's halo or migrate in from outside? If the latter, how? ... The Milky Way Galaxy has a system of roughly 150 globular clusters, which are all older than 9 billion years. ... Get instant access to subscriber content on Astronomy.com! ... If you are already registered on Astronomy.com, please log in below. ...

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. ...

Many intermediate-age star clusters in the Magellanic Clouds exhibit very unusual features in their colour-magnitude diagrams that suggest they may have formed their stars over periods spanning hundreds of millions of years per cluster. ... Nonetheless, this interpretation is enticing in the context of the formation of ancient globular clusters, which almost always exhibit puzzling abundance patterns that apparently require multiple episodes of star formation to explain. ...

Why areNuclear Star Clusters interesting? 1) Many -- if not all ­ nuclear star clusters appear to be young, or at least have a young population of stars. ... 3) If nuclear clusters indeed form in the galaxy center, their impact on the dynamics of stars and gas in the central region of the host galaxy needs to be understood, because it can potentially influence the galaxy morphology. For example, it has been suggested that nuclear clusters can destroy stellar bars and thus form galaxy bulges. ...

A Canadian and American team of Astronomers have used the 305-m wide Arecibo radio dish, the world's largest and most sensitive radio telescope, to uncover a dozen new super-fast-spinning pulsars. The team directed their search for these rare and exotic stars by pointing the Arecibo radio telescope towards massive star clusters, called Globular Clusters, orbiting our Milky Way galaxy. ... One of the most exotic residents in the Globular cluster system are the millisecond pulsars. ...

... The routines implemented are CLUSTER which has 8 options for hierarchical clustering and PARTITION which carries out non--hierarchical clustering. ... The former is non--hierarchical clustering or partitioning. The latter is hierarchical clustering. Brief consideration will show that a sequence of n-1 agglomerations are needed to successively merge the two closest objects and/or clusters at each stage, so that we have a set of n (singleton) clusters, n-1 clusters, ..., 2 clusters, 1 cluster. ...

... 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. ...

... 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. ...

... Archives . ... my first AAS. ... I was questioned by two attendees, acquainted before the AAS, if I can suggest them clustering methods relevant to their projects. ... classification vs. clustering or supervised learning vs. unsupervised learning : the former terms from the pairs indicate the fact that the scientist already knows types of objects in his hands. ... Tags: Classification , clustering , cosmology , spatial statistics , supervised learning , test , unsupervised learning . ...

... 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. ...

DSS input form . The SuperCOSMOS Sky Survey . ... Pi of the Sky . The Sloan Digital Sky Survey . ... Extragalactic DataBase . ... SIMBAD Astronomical Database . ... Query form . ... The Two Micron All Sky Survey. ... The NRAO VLA Sky Survey . ... NIST Atomic Spectra Database (Lines Form) . ... The UVES Paranal Observatory Project . ... Rochester Astronomy . ... European Southern Observatory . European Astronomical Society . ... Astronomical Society of the Pacific . ... Sat24 BTA on line . ...

The X-ray Fundamental Plane of Clusters of Galaxies Yutaka Fujita National Astronomical Observatory, Japan We analyze the relations among central gas density, core radius, and temperature of X-ray clusters by plotting the observational data in the three-dimensional (log  gas;0 , log r c , and log T gas ) space and nd that the data lie on a 'fundamental plane'. ... The two parameters describing the plane are formation redshift and temperature of clusters. ...

ABSOLUTE PROPER MOTIONS OF 331 OPEN CLUSTERS . ... The proper motions of stars in the fields of 331 open clusters were taken from Four-Million Star Catalog (4M-catalog) of positions and proper motions (Volchkov et al. ... The absolute proper motions for 21 young open clusters have been derived by comparison of precise relative proper motions of individual stars and their corresponding absolute proper motions. ... Sign of proper motions in RA . ... 0.0001 arcsec/yr . ... rms error in RA proper motion . ...