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. ...

... Johnson, K. E., Leitherer, C., Vacca, W. D., Conti, P. S. AJ, 120, 1273 (2000) . ... Sirianni, M., Nota, A., Leitherer, C., De Marchi, G., Clampin, M. ApJ, 533, 203 (2000) . B stars as a diagnostic of star formation at low and high redshift . ... Photon and metal production in starburst galaxies . ... Star formation in starburst galaxies . Leitherer, C. in Star Formation From the Small From the Small to the Large Scale, ed. F. Favata, A. A. Kaas, A. Wilson (Noordwijk: ESA), 37 (2000) . ...

... This paper ( Burke et al. 2003 ) describes the creation of one such catalogue - the Southern Serendipitous High-redshift Archival ROSAT Cluster (SHARC) survey - which covers an area of 17.7 deg 2 and consists of 32 clusters with redshifts between 0.05 and 0.7 and X-ray luminosities between 7 x 10 42 and 4 x 10 44 erg/s: the high-redshift subsample contains 16 clusters with = 0.3 and X-ray luminosities greater than 2 x 10 43 erg/s (luminosities are quoted for the 0.5 - 2.0 keV energy band). ... 1997 ...

... 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. ... The Hercules Cluster of Galaxies . ... Galaxies Away . ...

... 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 | ...