... 2004 October 12 . M3: Inconstant Star Cluster . ... Explanation: Star clusters appear constant because photographs of them are frozen in time. In reality, though, cluster stars swarm the center and frequently fluctuate in brightness. ... In fact, the above time lapse movie of bright globular cluster M3 was taken over a single night. Most of the variable stars visible above are RR Lyrae stars , stars that can quickly double their brightness while becoming noticeably bluer. ... About APOD | ...

... M3: Inconstant Star Cluster . ... Credit: J. Hartman K. Stanek ( Harvard CfA ) Explanation: Star clusters appear constant because photographs of them are frozen in time. In reality, though, cluster stars swarm the center and frequently fluctuate in brightness. ... Most of the variable stars visible above are RR Lyrae stars , stars that can quickly double their brightness while becoming noticeably bluer. ... Publications with keywords: M3 - globular cluster . ... Globular Star Cluster M3 . ...

... Bad Astronomy . ... Bitesize Astronomy . ... Last week's Snack talked about how black holes can affect the environment around them in such a way as to be very bright . ... It's a common misconception that black holes always have matter swirling into them. ... As this matter gets closer and closer to the black hole it piles up and a large, fairly flat disk forms. This is called the accretion disk , because matter from this disk accretes (that is, falls in) on the black hole. ... 2008 Phil Plait. ...

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. ...

... Kalirai and Harvey Richer of the University of British Columbia led the study, which began as an investigation of a globular star cluster in the Milky Way galaxy known as NGC 6397. ... Within the population of stars and galaxies behind NGC 6397, the Hubble image revealed a large elliptical galaxy that contains several hundred globular clusters. ... In fact, a single giant star in NGC 6397 appears 10 million times brighter than one of the distant globular clusters. ...

... May 22, 1996 . Star Cluster in the Rosette Nebula . ... Explanation: Embedded in the center of the colorful and photogenic Rosette Nebula is a bright, young open cluster . The bright blue stars in this cluster, labelled NGC 2244, emit ultraviolet light that knocks electrons away from hydrogen atoms . ... The Rosette Nebula is thousands of light years distant, but light would take only about 100 years to cross it. ... Tomorrow's picture: The Violent Star Cluster 30 Doradus . ... About APOD | ...

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... BLUE STRAGGLER STARS are unusually hot and bright stars found in the cores of ancient star clusters known as globulars. ... BACKGROUND (from wikipedia): Blue straggler stars are stars in open or globular clusters that are hotter and bluer than other cluster stars having the same luminosity. ... There is evidence in favor of this view, notably that blue straggler stars appear to be much more common in dense regions of clusters, especially in the cores of globular clusters. ...

In autumn 1994, two groups of astronomers announced that they had discovered Cepheid variable stars in a distant cluster of galaxies. ... As the term suggests, variable stars change in brightness over time. ... Variable stars are an ideal way to get high-school students doing real science, with real data, from the real sky. ... a sky chart to find the stars . ... Students can use the nearby stars to estimate the magnitude of Delta. ... Locate the star Delta in Cepheus and estimate its brightness . ...

ATMoB "Open Cluster Observing Award " Guidelines Purpose: To promote observing among the membership of the Amateur Telescope Makers of Boston through participation in the Open Clusters Observing Awards program. Introduction: This awards program is oriented towards visually observing open clusters above magnitude 9.9. ... It turns out that a very unprejudiced and convenient method to dermine the limiting magnitude is to count the number of visible stars in certain areas on the sky. ...

Results from 6m telescope observations of globular clusters in dwarf galaxies Sharina M. We consider properties of globular clusters in dwarf galaxies observed with the multi-slit unit of the SCORPIO spectrograph at the SAO 6m telescope. ... Studying GCs in dwarf galaxies at the faintest end of the galaxy luminosity function provides valuable information for a better understanding of galaxy evolution and evolutionary connection between globular clusters and nuclei of galaxies. ...

... All previous such superstars have been found along with many companion stars in the