... The relationship of the mass and the observed galactocentric distance R -- (a), and that of the mass and the total dissipation velocity n taken from Gnedin, Ostriker (1997) -- (b). The dotted line in diagram (a) shows the "cone of survival" according to the paper by Surdin and Arkhipova (1998) . ... The solid line is a regression stright line for the main sequence of clusters, and the dotted line parallel to it separates the sequence of clusters of anomalously small mass shown by open triangles. ...

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. ...

... The Matter of Galaxy Clusters . ... NASA Explanation: Situated over 2,000,000,000 ( two billion ) light-years from Earth, galaxies in cluster Abell 2390 (top) and MS2137.3-2353 (bottom) are seen in the right hand panels above, false-color images from the Hubble Space Telescope . ... While the Hubble images record the cluster's star-filled galaxies, the x-ray images show no galaxies at all ... only multi-million degree hot intracluster gas which glows in high energy x-rays. ...

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 | ...

... 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. ...

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! ...

... 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...

... 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. ...

Next: Cepheids in NGC Up: HST and the Previous: The Hubble Constant . ... Hubble Space Telescope observations of over a thousand globular clusters in the central region of M87 have been made using the WFPC-2. ... The Hubble Space Telescope offers several important advantages for measuring the globular cluster luminosity function for distant galaxies. ... W. B. Sparks, B. C. Whitmore, R. A. Lucas, F. Macchetto, J. BirettaSparks et al.HST Observations of Globular Clusters in M87 and an Estimate of . ...

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 . ...

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. ...

... 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. ...