Fundamental parameters and time evolution of mass loss are investigated for post-main-sequence stars in the Galactic globular cluster 47 Tucanae (NGC 104). ... We confirm the cluster's distance as d = 4611+213 -200 pc and age as 12 ТБ 1 Gyr. Horizontal branch models appear to confirm that no more red giant branch mass loss occurs in 47 Tuc than in the more metal-poor Я? Centauri, though difficulties arise due to inconsistencies between the models. ...

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: Other parameters of the Up: The Model Previous: Initial binary parameters . As we only deal with initially massive binary systems (their primary's mass is higher than 10 ), which are capable of evolving off the main sequence during less than years, the compact stars left behind stellar evolution are (in the case of the most massive stars) NSs and BHs. ... For a NS belonging to a binary, the evolution complicates as the secondary star evolves: for example, (recycling), etc. ...

... The most powerful and widely used methods to calculate the scattering matrix of a fractal cluster are based on the coupled dipoles methods (e.g. the Discrete Dipole Approximation, DDA) and the theory of light scattering by a cluster of spherical particles [2-4]. ... At present the procedure of calculation of the scattering matrix is well developed for both an oriented cluster of spherical particles and for chaotically oriented clusters of such particles [4]. ...

... The El Gordo Massive Galaxy Cluster . ... The above image of El Gordo is a composite of a visible light image from the Hubble Space Telescope , an X-ray image from the Chandra Observatory showing the hot gas in pink, and a computer generated map showing the most probable distribution of dark matter in blue, computed from gravitational lens distortions of background galaxies. ... Publications with keywords: galaxy cluster - dark matter . Publications with words: galaxy cluster - dark matter . ...

... 2014 April 22 . The El Gordo Massive Galaxy Cluster . Image Credit: NASA , ESA , J. Jee ( UC Davis ) et al. ... Dubbed "El Gordo", the seven billion light years ( z = 0.87) distant galaxy cluster spans about seven million light years and holds the mass of a million billion Suns. ... That galaxy is actually far in the background and has its image stretched by the gravitational lens action of the massive cluster. Follow APOD on: Facebook , Google Plus , or Twitter . ... About APOD | ...

... Science Users Information > Science Activities > PhD Thesis Topics offered by ESO Faculty Members > Thesis Topic: The onset of cluster formation near young high-mass stars . ... Observing with ESO Telescopes . ... ESO-MIDAS . ... ESO Data . ... We performed a NACO survey of massive young stellar objects (MYSOs) assessing the incidence of lower mass objects at angular scales 0:500 < d < 200 during the earliest, deeply embedded, phases of star formation. ... Return to list of thesis topics . ...

... 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. ...

... 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 . ...