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. ...

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! ...

Today's APOD | ... Editor's choices for the most educational Astronomy Pictures of the Day about globular clusters: . ... Explanation: Globular clusters once ruled the Milky Way . Back in the old days , back when our Galaxy first formed, perhaps thousands of globular clusters roamed our Galaxy . ... APOD: 2002 July 30 - A Star Cluster in Motion . ... Globular star clusters normally roam the halo of the Milky Way, ancient relics of our galaxy's formative years. ... Index | ... About APOD | ...

ST ScI Preprint #1362 . ... However, the radial extents of some of the very young clusters (ages <10 Myr) are much larger than those of old globular clusters (e.g., the outer radius of Knot S exceeds 450 pc). ... Star clusters around the edge of the dust overlap region appear to be the youngest, with ages 5 Myr, while clusters in the Western Loop appear to be 5-10 Myr old. ... A handful of old globular clusters from the progenitor galaxies are also identified. ...

... 22.09.2000 . ... Credit: B.J. Mochejska , J. Kaluzny ( CAMK ), 1m Swope Telescope Explanation: The fifty-fifth entry in Charles Messier's catalog, M55 is a large and lovely globular cluster of around 100,000 stars. ... Astronomers who make detailed studies of globular cluster stars can accurately measure the cluster ages and distances. ... Publications with keywords: star cluster - cluster - globular cluster - m55 . Publications with words: star cluster - cluster - globular cluster - m55 . ...

... 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. ...

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CHANDRA HRMA EFFECTIVE AREA Herman L. Marshall (MIT CXC) CHANDRA HRMA EFFECTIVE AREA Herman L. Marshall (MIT CXC) CHANDRA EFFECTIVE AREA ISSUES HRMA overlayer (with L. David, D. Jerius, etc.) ... 1, 2009 2 HLM-- Chandra Effective Area HRMA AREA MODEL, REVISED Motivation: No overlayer during ground cal (XRCF) Grating XRCF data shows overlayer Cluster kT values disagreed with XMM pn and MOS Pure overlayer models don't fit XRCF data 10 models tried None were perfect Few are very bad One picked: F Apr. ...

... For this paper: postscript PPEUC CMB index 1 Introduction.. ... We present a new model for the formation of spherically symmetric clusters in an expanding Universe. Both the Universe and the collapsing cluster are governed by the same pressure less fluid equations for which a uniform initial density profile is assumed. ... The computation of photon paths allows us to evaluate the gravitational effects imprinted on a Cosmic Microwave Background (CMB) photon passing through such an evolving mass. ...

Общая Астрономическая Конференция > Практика > Астрономический наблюдательно-информационный портал > Звездные ассоциации - шаровые скопления (поиск и описание) .. Шаровые скопления Терзяна (Terzan globular clusters) .. ... Поиск . ... Terzan 5 подробнее о шаровом скоплении читайте здесь (# 861 ) . ... Звездные ассоциации - шаровые скопления (поиск и описание) .. ... Messier 13 Great Globular Cluster in Hercules (M13) - шаровое скопление NGC 6205 (Melotte 150) в созвездии Геркулес (Hercules) .. ...

... The measurements extend to a lower 1.5 GHz limit of 1.0 mJy and comprise a complete sample with 1.5-GHz flux density 2.5 S1.5 J/AuJPh/47/145 VLA Survey of Rich Clusters of Galaxies II (Slee+, 1994) J/AuJPh/49/977 VLA Survey of Rich Clusters of Galaxies III (Slee+, 1996) ================================================================================ A VLA Survey of Rich Clusters of Galaxies II. ... Note (3): An elliptical Gaussian was fitted to the source. ...

... 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. ...

... 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. ...

... 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. ...

... 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. ...

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. ...

... Galactocentric distance dependences of the physical parameters of globular clusters. ... The straight line in (a) is the rms regression. The large circles in (b) show mean masses within narrow R intervals, and the solid lines show the rms regression fits for thick-disk and old-halo (left) and young-halo and corona (right) clusters. The dashed lines in (c) and (d) are upper and lower envelopes drawn by eye. discussion in the text | privious figure | next figure . ...

... 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. ...

... Tonight's Sky . ... The Magazine . News . Observing . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Open cluster NGC 2818, spiral galaxy NGC 2964, and spiral galaxy NGC 2976 . ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...

... About ATMoB . ... The Observing Committee is starting an Observing Awards Program to promote observing among the membership of the Amateur Telescope Makers of Boston. ... Participant must be a current member of the Amateur Telescope Makers of Boston . ... To qualify for your Observing Award Certificate, turn in your worksheet and drawings to an ATMoB Observing Committee member or observing@atmob.org . ... This Excel sheet has useful macros. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...