Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Astronomers Discover Mysterious New Star Clusters

05.04.2005


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, much greater within the newly discovered “extended clusters”.


The discovery was made during the course of an unprecedentedly broad and detailed survey of the Milky Way’s nearby sister, the Andromeda Galaxy (often referred to by the catalogue number, M31). The survey has so far covered more than 50 square degrees of sky, compared with only a few degrees covered by all previous CCD surveys.

Part of this study involved a search for globular clusters around M31, during which the new “extended clusters” were found. The new clusters are distributed in a spherical ‘halo’ region extending about 200,000 light years from the giant M31 spiral galaxy.

“How these objects formed, and why there are no similar clusters in the Milky Way is still a mystery,” said Avon Huxor, a PhD student at the University of Hertfordshire who is presenting a poster describing the new results at the RAS National Astronomy Meeting in Birmingham this week. “What is clear is that these clusters, like the globulars, are ancient. They are billions of years old - possibly amongst the first objects to form in the Universe.”

“It may be they were originally created not in M31, but as part of other small, so-called dwarf galaxies, which have subsequently between pulled apart and merged with the giant M31 galaxy,” commented team member Mike Irwin (University of Cambridge).

“That would be particularly exciting since they might then be more properly considered as the very smallest galaxies rather than star clusters, and help explain the apparent scarcity of such objects compared to theoretical predictions,” added Nial Tanvir, another University of Hertfordshire astronomer, who led this part of the work.

The data for the survey were acquired with the 2.5 m Isaac Newton Telescope in La Palma, Canary Islands, and the 3.6 m Canada-France-Hawaii Telescope in Hawaii. The observations were made using sensitive electronic CCD cameras; previous surveys of these regions had used photographic technology, which had failed to detect the faint clusters.

The team also included astronomers from France, Canada and Australia. A first paper announcing the discovery has been submitted to the Monthly Notices of the Royal Astronomical Society. Observations of the clusters with the Hubble Space Telescope are scheduled for later this year.

Dr. Nial Tanvir | alfa
Further information:
http://star-www.herts.ac.uk/~nrt/m31

More articles from Physics and Astronomy:

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>