... 2004 February 22 . The M7 Open Star Cluster in Scorpius . ... Explanation: M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars , can be seen with the naked eye in a dark sky in the tail of the constellation of Scorpius . ... The M7 star cluster has been known since ancient times, being noted by Ptolemy in the year 130 AD. ... About APOD | ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2000 February 28 . The Sombrero Galaxy from VLT . ... FORS1 , VLT ANTU , ESO . ... Reasons include the Sombrero 's unusually large and extended central bulge of stars, and dark prominent dust lanes that appear in a disk that we see nearly edge-on. Billions of old stars cause the diffuse glow of the extended central bulge. ... About APOD | ...

... 15.05.2011 . ... Credit Copyright: NASA , ESA , and the Hubble Heritage Team ( STScI / AURA ) Explanation: What's going on in the center of this spiral galaxy? Named the Sombrero Galaxy for its hat-like resemblance, M104 features a prominent dust lane and a bright halo of stars and globular clusters . Reasons for the Sombrero 's hat -like appearance include an unusually large and extended central bulge of stars, and dark prominent dust lanes that appear in a disk that we see nearly edge-on . ...

Astronotes Armagh Planetarium's Stellar Blog! ... Stars . ... Starbursts are short-lived events, stars are forming so quickly that the reservoirs of interstellar gas from which stars are coalescing would be used up on a timescale much shorter than the age of the galaxy . ... Strong stellar winds from giant new stars in the starburst region combine with the blasts of supernovae to push a mighty flood of extremely hot gas, a ?superwind? from the galaxy thousands of light years into intergalactic space. ...

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... The Pleiades star cluster, also known as the Seven Sisters and Messier 45, is a conspicuous object in the night sky with a prominent place in ancient mythology . ... The stars in the Pleiades are thought to have formed together around 100 million years ago, making them 1/50th the age of our sun, and they lie some 130 parsecs (425 light years ) away. ... Data for these stars are listed in a table below. ... Yes . ... WEBDA Pleiades cluster data . ... M45: The Pleiades Star Cluster (2007 November 18) ...

... These Frontier Fields will combine the power of HST with the natural gravitational telescopes of high-magnification clusters of galaxies. ... We are soliciting gravitational lensing maps for the last four Hubble Frontier Fields clusters (MACSJ0717.5+3745, MACSJ1149.5+2223, AbellS1063, and Abell 370) based upon the exceptionally deep HST FF imaging and other new ancillary data. ... For the full set of proposal instructions and requirements, see the FY16 Frontier Fields Lensing Map Call for Proposals....

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. ...

... a spiral galaxy some million light years away, made by combining images . ... 1st February using the Armagh Robotic Telescope at the Armagh Observatory. ... Image credit: Simon Jeffery. Astronomers Simon Jeffery and Jack Wright have obtained their first images of deep-space objects using a new тАЬroboticтАЭ telescope at Armagh Observatory. ... Simon Jeffery, project scientist for the new telescope, said: "After two years of hard work, it is very satisfying to see the first images looking so good. ...

... Bad Astronomy . ... Bitesize Astronomy . ... The next step up are true clusters, called open clusters . Open clusters (sometimes misleadingly called "galactic clusters") are groups of stars ranging in size from a few dozen stars up to tens of thousands. ... The youngest is about 1 or 2 million years old, while the oldest is about 6 or 7 billion years, making it just older than our own solar system. ... So by looking at the stars in the cluster we can tell pretty well how old they are. ...