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 | ...

... NGC 4755: A Jewel Box of Stars . ... Credit Copyright: Michael Bessell ( RSAA, ANU ), MSO Explanation: The great variety of star colors in this open cluster underlie its name: The Jewel Box . ... Open clusters are younger, contain few stars, and contain a much higher fraction of blue stars than do globular clusters. ... Publications with keywords: open cluster - NGC 4755 . Publications with words: open cluster - NGC 4755 . ... M7: Open Star Cluster in Scorpius . ... M6: The Butterfly Cluster . ...

... 87.1083Owen+ VIII/29 1400-MHz Survey of 1478 Abell Clusters of Galaxies (Owen+ 1982) ================================================================================ A 1400-MHz Survey of 1478 Abell Clusters of Galaxies Owen F.N., White R.A., Hilldrup K.C., Hanisch R.J. =1982AJ.. ... 0,] Major axis error 70- 71 A2 --- n_MajAxi *[ A, B, C,NR, ] Major axis note 73- 74 I2 arcmin MinAxi *? ... Note on dist-C: Ratio of the distance of the source from the cluster center to the corrected Abell cluster...

... 2000 August 4 . M15: Dense Globular Star Cluster . ... In fact, only 40,000 light-years away in the constellation Pegasus, M15 is one of the most densely packed globular star clusters in our Milky Way Galaxy. This stunning Hubble Space Telescope image of M15 shows thousands of individual stars across the central 10 or so light-years of the cluster, also cataloged as NGC 7078. ... Globular star clusters harbor from a hundred thousand up to a million stars and roam the Milky Way halo. ...

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. ...

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. ...

... 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. ...

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! ...

. 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 .

... 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! ...

... Posts tagged ?Globular Clusters? Oct 26th, 2007| 06:52 pm | ... I hope there are a paper or two drags your attentions and stimulates your thoughts in astrostatistics from arXiv. ... ArXiv] 4th week, Oct. ... Tags: Astrometry , Bayesian , Change Point , Globular Clusters , Matching , X-ray Binaries . ... This week, instead of only filtering AstroStatistics related papers from arxiv, I chose additional arxiv/astro-ph papers related to CHASC folks? astrophysical projects. ... ArXiv] 1st week, Oct. ...

... We address a question if globular clusters (GC) in a protogalaxy could for some time evolve chemically as isolated systems, enriching themselves with heavy elements produced in first supernova events that follow initial star formation. We determine both the critical mass of a protoglobular cluster that is needed to retain the ejecta of the very first supernova, and the critical energy (i.e., number of supernovae) that is needed to expel the residual gas from a cluster of a given mass. ...

... 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. ...

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. ...

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 . ...

Searching for Ultra Compact Binaries in Globular Clusters What Are Ultra Compact Binaries? ... An ultra compact binary is a binary that consists two white dwarf To source the FITS files that contained the UV images, the sky coordinates stars and has an orbital period shorter than ~70min (A binary and the details on brightness for each star in each globular cluster we were consists of two stars orbiting around their centre of mass, it enables investigating, we used the XMM online archive. ...

... Bad Astronomy . ... Bitesize Astronomy . ... The last step encompassed them all with galaxies , and how we discovered that the Milky Way was not the entire Universe. ... And just like those star clusters, there are different kinds of galaxy clusters. ... There are vast clusters of clusters, called superclusters, which contains hundreds of thousands or even millions of galaxies. ... Our own Galaxy has 400 billion stars in it, yet there are clusters out there with millions of galaxies like our own. ...

... 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. ...

... ATNF Home . About ATNF . ... About ATNF overview . ... Governance overview . Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Parkes radio telescope . ... Visiting Parkes radio telescope . ... Parkes radio telescope webcam . ... RV Tau Variables in Globular Clusters - clues on their nature? ... This is a report of the detailed elemental abundances of RV Tau variables that reside in globular clusters, and how they compare with RV Tau variables in the field. ...

Central Bodies Masses of Selected Globular Clusters N.A.Shakht, A.A.Kiselev, Yu.N.Gnedin and E.A.Grosheva. The Main Astronomical (Pulkovo) Observatory RAS 47 Tuc ­NGC 104 RA 00 24 .1 Dec -72° 04 .9 Size = 30.9 mvis + 4. 0 m D from = 12,1 kpc, h m Cen - NGC 5139 NGC 6397 (Ara) RA 17 h40.m7 Dec -53o 40'.4 Size = 31',0 mvis + 5,3m D from =2.3 kpc RA 13h 26m .8 Dec -47° 28 6 Size = 36.3 m vis +3. 7 m D from =15.8 ±1.1 kpc, 12109 years, Age: 10109 years, (13.4 ± 0.8)109 years. ...