Latest Globular cluster Stories
A new Hubble image of the Antennae galaxies is the sharpest yet of this merging pair of galaxies. As the two galaxies smash together, thousand of millions of stars are born, mostly in groups and clusters of stars. The Universe is an all-action arena for some of the largest, most slowly evolving and surprising processes known to mankind. A new picture taken by the Advanced Camera for Surveys (ACS), onboard the NASA/ESA Hubble Space Telescope, shows the best ever view of the Antennae...
A study of the Universe's most massive galaxy clusters has shown that mergers play a vital role in their evolution. Astronomers at Oxford University and the Gemini Observatory used a combination of data from the twin Gemini Telescopes, located in Hawaii and Chile, and the Hubble Space Telescope (HST) to study populations of stars in the Universe's most massive galaxy clusters over a range of epochs "“ the earliest being half the age of the Universe. The HST images were used to map...
"Space is big. Really big. You just won't believe how vastly hugely mind-bogglingly big it is." -- Douglas Adams, "The Hitchhiker's Guide to the Galaxy" NASA -- It is the job of astronomers to put numbers on the stupefying vastness of space and the objects it holds. That's how they get the universe to spill its secrets. The University of Virginia's Steve Majewski and his team plan to use NASA's SIM PlanetQuest space telescope to make ultra-precise measurements that will...
VLT Study Reveals Troubled Past of Globular Cluster Messier 12 ESO -- Based on observations with ESO's Very Large Telescope, a team of Italian astronomers reports [1] that the stellar cluster Messier 12 must have lost to our Milky Way galaxy close to one million low-mass stars. "In the solar neighbourhood and in most stellar clusters, the least massive stars are the most common, and by far", said Guido De Marchi (ESA), lead author of the study. "Our observations with ESO's VLT...
Cambridge, MA -- Gamma-ray bursts are the most powerful explosions in the universe, emitting huge amounts of high-energy radiation. For decades their origin was a mystery. Scientists now believe they understand the processes that produce gamma-ray bursts. However, a new study by Jonathan Grindlay of the Harvard-Smithsonian Center for Astrophysics (CfA) and his colleagues, Simon Portegies Zwart (Astronomical Institute, The Netherlands) and Stephen McMillan (Drexel University), suggests a...
UCLA -- An international team of astronomers reported evidence for the formation of mysterious "super star clusters" Jan. 9 at the annual meeting of the American Astronomical Society in Washington, D.C. These star clusters are the likely precursors to the familiar globular clusters of the Milky Way; however in our galaxy, globular clusters are all believed to be older than 10 billion years -- close to the age of the universe itself -- and none are forming. Using the Very Large Array...
The University of Chicago's Nicolas Dauphas has developed a new way to calculate the age of the Milky Way that is free of the unvalidated assumptions that have plagued previous methods. Dauphas' method, which he reports in the June 29 issue of the journal Nature, can now be used to tackle other mysteries of the cosmos that have remained unsolved for decades. "Age determinations are crucial to a fundamental understanding of the universe," said Thomas Rauscher, an assistant professor...
The University of Chicago's Nicolas Dauphas has developed a new way to calculate the age of the Milky Way that is free of the unvalidated assumptions that have plagued previous methods. Dauphas' method, which he reports in the June 29 issue of the journal Nature, can now be used to tackle other mysteries of the cosmos that have remained unsolved for decades. "Age determinations are crucial to a fundamental understanding of the universe," said Thomas Rauscher, an assistant professor...
RAS -- Using two orbiting X-ray telescopes, a team of international astronomers has examined distant galaxy clusters in order to compare them with their counterparts that are relatively close by. Speaking today at the RAS National Astronomy Meeting in Birmingham, Dr. Ben Maughan (Harvard-Smithsonian Center for Astrophysics), presented the results of this new analysis. The observations indicate that, despite the great expansion that the Universe has undergone since the Big Bang, galaxy...
RAS -- A UK-led team of astronomers has discovered a completely new type of star cluster around a neighbouring galaxy. The new-found clusters contain hundreds of thousands of stars, a similar number to the so-called "globular" star clusters which have long been familiar to astronomers. What distinguishes them from the globular clusters is that they are much larger "“ several hundred light years across "“ and hundreds of times less dense. The distances between the stars are, therefore,...
Latest Globular cluster Reference Libraries
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...
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...
Galaxy -- Stars are almost always found in collections called galaxies, together with gas, dust, and large amounts of dark matter detected by its gravitational effects. These are all held together by gravitational attraction and orbit a common centre. There is some evidence that black holes may exist at the centre of some or most galaxies. Galaxies come in three main types: ellipticals, spirals, and irregulars. A slightly more extensive description of galaxy types is given by the Hubble...
Virgo A Galaxy -- Discovered 1781 by Charles Messier. The giant elliptical galaxy M87, also called Virgo A, is one of the most remarkable objects in the sky. It is perhaps the dominant galaxy in the closest big cluster to us, the famous Virgo Cluster of galaxies (sometimes also called "Coma-Virgo cluster" which is more acurate, as it extends into constellation Coma), and lies at the distance of this cluster (about 60 million light-years). M87 lies well in the heart of the Virgo cluster...
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...
