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. ...

... Science . ... Science Users Information > Science Activities > PhD Thesis Topics offered by ESO Faculty Members > Studying the Cosmological Evolution of Galaxy Clusters with (Sub-)mm Observations . ... Data Handling and Products . ... ESO Data . ... Studies of the Planck data set with optical and sub-mm follow-up observations give new insights about the early assembly of the first clusters, and the later evolution of their gas content as well as of their population of star-forming galaxies. ...

... Australia Telescope Steering Committee . ... Parkes radio telescope . ... Late Stages of Stellar Evolution . Welcome to the home page of the Late Stages of Stellar Evolution" We are a research group which operates within the Astrophysics Group of the Australia Telescope National Facility. ... To investigate the late stages of stellar evolution and in particular the role of stellar mass-loss in the evolution of asymptotic giant branch stars, proto-planetary nebulae and extremely massive stars. ...

... Conditions are like those inside a white dwarf. ... It is not well understood what changes are caused inside the star, but the star certainly loses mass between leaving the main sequence and becoming a helium-burning horizontal branch star. When core helium burning ends, the low mass star rejoins the asymptotic giant branch, where the hydrogen and helium burning shells interact, causing a series of thermal pulses. ... Stars less than one third of a solar mass will not ignite helium at all. ...

... 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 ( ). ...

... 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. ...

... Observing . ... Subscriber Extras . ... Web Extras . ... Globular cluster NGC 2808, elliptical galaxy NGC 2986, and the Sextans Dwarf . ... Observing springtime deep-sky objects with a large telescope . ... Web Extra: Astronomers animate one of the largest galaxy clusters ever observed . ... At the center of the Phoenix Cluster, a large elliptical galaxy lurks where the hot gas is ejected, giving off unprecedented levels of X-rays, which have been observed by the orbiting Chandra X-ray telescope. ...

... The study of the Large-scale structure of the Universe and measurements of the Dark Energy equation of state; The exploration of the growth and cosmological evolution of supermassive Black holes in the Universe. ... In course of the all sky survey SRG will discover about 100 000 galaxy clusters and 3 million AGNs. Galaxy clusters are the largest gravitationally bounded objects in the Universe and are best explored through the study of X-ray emission from the hot intergalactic gas. ... 2016 IKI RAN ...

... 2000, ApJ, 537, L49 . ... F. Palla . Invited Talk at the IAU Symposium 200 "The formation of binary stars" eds. R.D. Mathieu and H. Zinnecker (ASP Conf. Ser.) in press . Optical follow-up of ROSAT discovered candidate members of the open cluster Coma Berenices . ... 2000, A , in press . ... 2000, ApJ, in press . ... 2000, ApJ, in press (Sept. ... 2000, ApJ Lett., in press . ... Click to examine publications from other years . ... Star Formation Group . ... Arcetri Home Page . ...

... The observed isotropy on the sky and non-uniform spatial distribution of gamma-ray bursts   (GRB) revealed by the BATSE   device onboard the Compton Gamma-Ray Observatory (e.g. Meegan et al. , 1992)[ 138 ] lend support to the idea of a cosmological origin of GRB (Prilutski and Usov, 1975;[ 165 ] Usov and Chibisov, 1975)[ 199 ] for which the best candidates could be merging binary NS+NS   or NS+BH   at high redshifts (z 1 -2), (Blinnikov et al. ... Calculation of Binary Neutron Star Coalescence Rates...

... 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. ... Abell 370: Galaxy Cluster Gravitational Lens . ...