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. ...

Next: Star Formation Rate and Up: No Title Previous: Calculation of Evolutionary Tracks . To start calculations, we choose the distributions of the initial binary parameters: the mass of the primary ZAMS component, , binary mass ratio, , orbital separation a . ... whereas the mass ratio distribution is not. ... The zero assumption often made is that the mass ratio distribution has a flat shape, that is binaries with a high mass ratio occur as frequently as those with equal masses. ...

Topics covered by the IAU Symp. ... Do all galaxies have stellar halos? ... Stellar tracers of the MW halo and nearby galaxies; the stellar population of star clusters and their contribution to the galaxy halos . ... NEW: Scientific program of the IAU Symposium 317 can be downloaded here . ... GLOBAL PROPERTIES OF STELLAR HALOS FROM THE MILKY WAY TO EXTERNAL GALAXIES . ... DISCRETE CONSTITUENTS OF STELLAR HALOS IN THE MILKY WAY AND IN EXTERNAL GALAXIES : PLANETARY NEBULAE and GLOBULAR CLUSTERS . ...

... Keywords: globular clusters,M3,photometry,HST . ... Perform the most accurate test of the ``stellar clock'' used in dating globular clusters. ... These data will provide the first complete sample of post-main sequence stars over the entire area of the cluster, and will allow the most stringent tests of stellar evolution and dynamics models. ... M3 contains the largest population of Blue Straggler Stars (BSS) detected in a globular cluster so far ( ). ...

... Stellar cinders . Born-again stars . ... Heavyweight Stars . ... What will happen inside the Sun and why? ... These are questions about "stellar evolution", the history of stars as they are transformed by nuclear processes deep inside. ... Most of what we know about stellar evolution comes from computer models of stars. ... We learn about the evolution of high-mass stars from HR diagrams of young galactic open clusters, and the evolution of low-mass metal-poor stars from old globular clusters. ...

Simulating the Evolution of Stellar Clusters ? ... Resonant Exchange (few Myr) 4perturbed: 6000d, e=0.94 4CE + CE - DWD (0.35d) 2.0 MS 0.8 WD 4GR - merger after 10 Gyr M = 1.6 Msun Comparison with Data: Simulation of M67 H 12,000 single stars (KTG1993 IMF: 0.1 - 50 Msun ) H 12,000 binaries (q: uniform, e: thermal, a: flat-log, max 50 au) H Z = 0.02 H Circular orbit at Rgc = 8 kpc H Plummer Sphere in virial equilibrium 4M ~ 18700 Msun 4 Rt = 32 pc 4Trh ~ 200 Myr 4s ~ 3 km/s 4nc ~ 200 ...

... The evolution of magnetic fields in OB-type stars from the study of open clusters of different ages . ... Wade G. A. The MiMeS Project: Magnetism in Massive Stars . ... Polosukhina N., Shavrina T., Drake N., Kudryavtsev D. Smirnova M. New results of the spectral observations of CPstars in the Li I 6708? spectral region with BTA telescope of SAO RAS . ... Magnetic Stars-2010 . ... List of participants . List of reports . ... Laboratory for the Stellar Magnetism Study of SAO of the RAS . ...

... Archives . ... One of the speakers from the google talk series exemplified model based clustering and mentioned the likelihood ratio test (LRT) for defining the number of clusters. ... The LRT is worthless for testing a mixture when the set of parameters is large . ... We prove in this paper that the LRT is worthless from testing a distribution against a two components mixture when the set of parameters is large. ... Category: arXiv , Bad AstroStat , CHASC , Frequentist , Stat | Comment ( RSS ) | ...

... Contacts . 2012: . ... We refined the fundamental parameters of the components, the orbital periods, and the conditions of photospheric heating of the secondary component by the ultraviolet radiation of the hot component. ... The observations of the star clusters associated with ultra-luminous x-ray sources (ULXs) in four galaxies on the 6-meter and VLT telescopes have shown that all the ULXs are located within 200pc of very young star clusters (younger than 5 million years). ... Archive . ...

... 05/09/2013 Galaxy Evolution over Five Decades - Cambridge 2013 Nuclear activity and environment Effect of environment on AGN is not completely clear yet. ... 05/09/2013 Galaxy Evolution over Five Decades - Cambridge 2013 Effect of the mass Mass slices ­ optical and radio AGN overall interaction one-on-one interaction relative location 05/09/2013 Galaxy Evolution over Five Decades - Cambridge 2013 Stratified study Stratifed study that considers several strata of mass. ...

... A technique allowing automatic representation by a relatively small number of independent parameters based on the principal component analysis of data sequences is presented. ... In recent years the spectrum of observed astronomical data can be characterized as greatly varied. ... In this instance, the problem of initial description and classification of newly-observed data becomes most urgent, especially if there is a lack of preliminary observational material and theoretical expectations. ...

... The obtained results lead to the following conclusions: a) the heavy element enrichment had taken place in the Galaxy in a few bursts of its activity rether than in a continuons manner; b) these bursts occured during the callapse of the early Galaxy; c) the star formation had been inhibited in the time of the bursts; d) the metal enrichment did not proceed in the periods of star formation, between these bursts of activity. ...

... Астронет | ... планета Астронет | ... An investigation of the structure of non-uniformities of interstellar absorption using photometry of globular clusters . ... L. N. Berdnikov; D. G. Turner . A search for evolutionary changes in the periods of Cepheids using archival data from the Harvard observatory plate collection I: VY, WZ and GH Carinae . ... Study of changes in the periods of population II Cepheids in globular clusters I: M2 . ... A. O. Allakhverdiev; S. O. Tagiyeva; O. H. Guseinov . ...

... 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. ...

home education > activities . ... Quick math activity that asks students to calculate scale models of a binary star system with a black hole in it. [h] . ... Students use a radiometer and a light bulb with a dimmer switch to make connections between the temperature, color, and radiation output of a star. ... This demonstration, similar to the above, from the Exploratorium Snack-book of science activities, lets students demonstrate how molecules scatter light and change the colors of the beam. [m,h] . ...

... HI mass fractions Comparison samples HeViCS bright galaxy Catalogue(BGC) Davies+2012 Average scaling relations for HI-normal and extremely HI-deficient galaxies in H3 survey (Gavazzii+ 2013 ) Dwarf galaxy survey (DGS) Madden+ 2013 KINGFISH Kennicutt 2011 Specific star formation rates Schiminovich +2007 Comparison samples HeViCS bright galaxy Catalogue(BGC) Davies+2012 Dwarf galaxy survey (DGS) Madden+ 2013 KINGFISH Kennicutt 2011 Dust ...

... 145Slee,Roy Savage We present detailed radio and optical parameters for the stronger radio sources in 58 Abell cluster fields observed with the Very Large Array (VLA) using scaled arrays at 1.5 and 4.9 GHz. ... The cluster fields were distributed over 24 h of RA and between declinations +35 deg and -30 deg. ... Optical identifications Cluster Source Radio Centroid Optical Position EF Ang. ...

... 2007 March 5 . Illusion and Evolution in Galaxy Cluster Abell 2667 . ... Explanation: What's happening to the galaxies of cluster Abell 2667? ... To start, most of the yellowish objects in the above image from the Hubble Space Telescope are galactic members of a massive cluster of galaxies known as Abell 2667 . ... Light from this galaxy is gravitationally lensed by Abell 2667, appearing much like a distant person would appear through a wine glass. ... About APOD | ...

The new view on the population of Galactic open clusters A.E.Piskunov1, N.V.Kharchenko2, S.RЖser3, E.Schilbach3, R.-D.Scholz4 1 2 3 4 Institute of Astronomy, Moscow, Russia Main Astronomical ... Observatory, Kiev, Ukraine Astronomisches Rechen-Institut, Heidelberg, Germany Astrophysikalisches Institut Potsdam, Germany What are open clusters and what do they teach us Groups of Population I ... Cluster complexes: OCC-1 = Gould's Belt cluster complex? ...

... 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. ...