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Latest Star clusters Stories

74f33522edfebf379b88498f847dd79f1
2009-12-23 14:20:00

Using the NASA/ESA Hubble Space Telescope, astronomers have uncovered two distinct kinds of "rejuvenated" stars in the globular cluster Messier 30. A new study shows that both stellar collisions and a process sometimes called vampirism are behind this cosmic "face lift". The scientists also uncover evidence that both sorts of blue stragglers were produced during a critical dynamical event (known as "core collapse") that occurred in Messier 30 a few billion years ago. Stars in globular...

4fbebe452a31bf3fe0aafb624c3ecb551
2009-12-23 14:15:55

For almost 50 years, astronomers have puzzled over the youthful appearance of stars known as blue stragglers. Blue stragglers are the timeworn Hollywood starlets of the cosmos: They shine brightly, they are older than they appear, and they have, disconcertingly, gained mass at a late stage of life. "These blue, luminous stars should have used up their hydrogen fuel and flamed out long ago," explains Robert Mathieu, a University of Wisconsin-Madison astronomer. "Yet they are still here. By...

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2009-10-29 09:20:00

Star clusters are among the most visually alluring and astrophysically fascinating objects in the sky. One of the most spectacular nestles deep in the southern skies near the Southern Cross in the constellation of Crux. The Kappa Crucis Cluster, also known as NGC 4755 or simply the "Jewel Box" is just bright enough to be seen with the unaided eye. It was given its nickname by the English astronomer John Herschel in the 1830s because the striking color contrasts of its pale blue and orange...

03ce92324db663537810a077060a51261
2009-07-09 15:40:00

The tight cluster of stars surrounding a supermassive black hole after it has been violently kicked out of a galaxy represents a new kind of astronomical object and a fossil record of the kick. A paper published in the July 10 issue of The Astrophysical Journal discusses the theoretical properties of "hypercompact stellar systems" and suggests that hundreds of these faint star clusters might be detected at optical wavelengths in our immediate cosmic environment. Some of these objects may...

326847e802c0b0af5991c9192dab92641
2009-01-14 16:01:46

Researchers have discovered that the mysterious overweight stars known as blue stragglers are the result of "Ëœstellar cannibalism' where plasma is gradually pulled from one star to another to form a massive, unusually hot star that appears younger than it is. The process takes place in binary stars "“ star systems consisting of two stars orbiting around their common centre of mass. This helps to resolve a long standing mystery in stellar evolution. The research, which is part...

dca005aee45ff0614aeddb3efad2a0671
2008-12-04 09:30:00

Like a whirl of shiny flakes sparkling in a snow globe, Hubble catches an instantaneous glimpse of many hundreds of thousands of stars moving about in the globular cluster M13, one of the brightest and best-known globular clusters in the northern sky. This glittering metropolis of stars is easily found in the winter sky in the constellation Hercules and can even be glimpsed with the unaided eye under dark skies. M13 is home to over 100,000 stars and located at a distance of 25,000...

a05c699ddc1b2e013653e6f7fcf44ddd1
2008-08-20 18:35:00

Black holes are sometimes huge cosmic beasts, billions of times the mass of our sun, and sometimes petite with just a few times the sun's mass. But do black holes also come in size medium? A new study suggests that, for the most part, the answer is no. Astronomers have long suspected that the most likely place to find a medium-mass black hole would be at the core of a miniature galaxy-like object called a globular cluster. Yet nobody has been able to find one conclusively. Now, a team of...

dcf813ec6505513ef6664b9b211b3d751
2008-08-05 12:10:00

Globular star clusters, dense bunches of hundreds of thousands of stars, have some of the oldest surviving stars in the universe. A new study of globular clusters outside our Milky Way Galaxy has found evidence that these hardy pioneers are more likely to form in dense areas, where star birth occurs at a rapid rate, instead of uniformly from galaxy to galaxy. Astronomers used NASA's Hubble Space Telescope to identify over 11,000 globular clusters in the Virgo cluster of galaxies. Most are...

e1f58458ac3284b3c2a9c74d487d0854
2008-07-10 08:00:00

Imagine having three clocks in your house, each chiming at a different time. Astronomers have found the equivalent of three out-of-sync "clocks" in the ancient open star cluster NGC 6791. The dilemma may fundamentally challenge the way astronomers estimate cluster ages, researchers said. Using NASA's Hubble Space Telescope to study the dimmest stars in the cluster, astronomers uncovered three different age groups. Two of the populations are burned-out stars called white dwarfs. One group of...

2323bf4e91bc15fc864aef16ded436151
2008-04-29 08:45:00

Some of the oldest objects in the Universe may still have a long way to go, according to a new study using NASA's Chandra X-ray Observatory. These new results indicate that globular clusters might be surprisingly less mature in their development than previously thought.Globular clusters, dense bunches of up to millions of stars found in all galaxies, are among the oldest known objects in the Universe, with most estimates of their ages ranging from 9 to 13 billions of years old. As such they...


Latest Star clusters Reference Libraries

6_ee73912f0568b7aab1fb32a3d250b7b82
2004-10-19 04:45:42

Star Cluster -- Star clusters are physically bound systems of stars. In order of low compactness to high compactness (and in some sense also age) they range from stellar associations to open clusters to globular clusters. Star clusters are held together by the gravitation of their members. Due to both external (encounters with massive objects, influence of the host galaxy) and internal (encounters with other cluster members, stellar evolution) influences, clusters slowly evaporate. Their...

6_d262fe26be108a60a9b76138f3306a692
2004-10-19 04:45:42

Open Cluster -- An open cluster is a group of star formed from a molecular cloud, the illuminated parts of which we see as one or more nebulae. They are also called galactic clusters since they exist within the galaxy. All the stars in an open cluster have more or less the same age and the same chemical composition, so any difference between them is solely due to their mass. Most open clusters are dominated by their O-type and B-type giant blue stars, which are very luminous but...

6_46f1290db7aabf07d0480393fea260ed2
2004-10-19 04:45:41

Globular Cluster -- A globular cluster is a cluster of stars that is spherical in shape and extremely dense towards its core. Globular clusters are usually composed of hundreds of thousands of old stars, similar to the bulge of a spiral galaxy but confined to a volume of only a few cubic parsecs. Some globular clusters (like Omega Centauri in our Milky Way, and G1 in M31) are truly massive clusters, with several million times the mass of our Sun. Such globular clusters may be the...

3_b44b7fd989f2076cfeda5fc743f39ab02
2004-10-19 04:45:40

Milky Way Galaxy -- The Milky Way (a translation of the Latin Via Lactea, in turn derived from the Greek Galaxia (gala, galactos means "milk")) is a hazy band of white light across the night sky formed by billions of stars in the disc of our galaxy. The Milky Way appears brightest in the direction of Sagittarius, where the galactic centre lies. Relative to the celestial equator, the Milky Way passes as far north as the constellation of Cassiopeia and as far south as the constellation of...

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