Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Million-star cluster in nearby galaxy reported

06.06.2003


A small, bizarre cluster of a million young stars, enshrouded in thick gas and dust in a nearby dwarf galaxy, has been confirmed by Jean Turner, UCLA professor of physics and astronomy, and her colleagues, in the June 5 issue of the journal Nature.


Pseudo-color image of dwarf galaxy NGC 5253.
Blue: adapted from Hubble Space Telescope optical image; red: infrared image from the Keck Telescope. The supernebula/embedded million-star young cluster is the brightest infrared source, visible to the upper right of the central bright optical star cluster. Courtesy: D. Calzetti, Space Telescope Science
Institute.


Infrared picture of the starburst and forming super star clusters in the
dwarf galaxy NGC 5253. The "supernebula"/embedded million-star cluster is the brightest infrared source, near the center of the plot. Courtesy: UCLA Astronomy.



Turner and her colleagues estimate that the stars are still in the process of forming, and are less than a million years old — extremely young by astronomical standards.

The cluster contains more than 4,000 massive “O” stars, each a million times brighter than our sun, with more than 30 times the mass of our sun. “O” stars blow off violent winds, and are the most luminous of all known stars. These “O” stars will become supernovae and explode at the end of their lives, but none has done so yet.


“This is the first time such a large cluster of ‘O’ stars, bound with its natal gas, has been observed anywhere in the universe,” Turner said. “These ‘O’ stars should not fit in this small region, yet somehow they do.”

The research is federally funded by the National Science Foundation.

The star cluster is buried within a “supernebula” consisting of hot gases in the galaxy NGC 5253, in the southern part of the sky, slightly above the horizon, in the constellation Centaurus. The supernebula is hidden from optical view by its own gases.

The astronomers used the Keck Observatory’s Near Infrared Spectrometer, an instrument built by Turner’s UCLA astronomy colleague, professor Ian McLean, to study the star cluster.

The stars are packed tightly in a region only three light years across — less than the distance from our sun to its closest neighbor star, Turner said.

The star cluster is surrounded by thick gases that move faster than 100,000 miles per hour — faster than the speed of sound — yet they are trapped by gravity.

“The dense gases are bound by the enormous gravity of the cluster, which makes this cluster different from any other known young cluster,” Turner said. “It’s truly a unique object. I originally titled this paper, ‘Supernebula in Gravitational Bondage.’ Clusters in our galaxy are not nearly as massive and cannot trap their gas.”

In the Milky Way, globular clusters containing hundreds of thousands of stars are billions of years old, having formed early in our galaxy’s history. Some astronomers had believed globular clusters could form only in the early universe, yet this nearby galaxy is forming globular clusters.

“It’s a mystery why this tiny galaxy can form globular clusters at the present time and the Milky Way can’t,” Turner said. “We hope to be able to solve this mystery. How a million stars can form in such a small region is also a mystery.”

The cluster has one billion times the luminosity of our sun, but is invisible in ordinary light. Turner’s team detected the cluster using infrared and radio observations. The astronomers detected the radio emission of the object in 1996, but needed the new infrared analyses to exclude possibilities other than the star cluster, and to see that the gases are trapped by gravity, Turner said.

Turner and her colleagues — Sara Beck, astronomy professor at Tel Aviv University’s School of Physics and Astronomy in Israel; former UCLA astronomy graduate students Lucian Crosthwaite and David Meier; James Larkin, assistant professor of physics and astronomy at UCLA; and Ian McLean, professor of astronomy at UCLA — analyzed infrared hydrogen spectra from NGC 5253, a galaxy that contains hundreds of large star clusters.

Turner and her colleagues will look for other examples of young star clusters, and hope to learn more about star formation within this cluster, using infrared and radio emissions.

“We haven’t observed this type of start formation before,” Turner said. “This globular cluster is invisible to ultraviolet telescopes, and could remain invisible for most of its star-forming lifetime.”

Stuart Wolpert | EurekAlert!
Further information:
http://www.ucla.edu/

More articles from Physics and Astronomy:

nachricht Return of the Blob: Surprise link found to edge turbulence in fusion plasma
27.05.2020 | DOE/Princeton Plasma Physics Laboratory

nachricht NIST researchers boost microwave signal stability a hundredfold
26.05.2020 | National Institute of Standards and Technology (NIST)

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: Biotechnology: Triggered by light, a novel way to switch on an enzyme

In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".

Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...

Im Focus: New double-contrast technique picks up small tumors on MRI

Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.

researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...

Im Focus: I-call - When microimplants communicate with each other / Innovation driver digitization - "Smart Health“

Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.

When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...

Im Focus: When predictions of theoretical chemists become reality

Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.

Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...

Im Focus: Rolling into the deep

Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

New 5G switch provides 50 times more energy efficiency than currently exists

27.05.2020 | Information Technology

Return of the Blob: Surprise link found to edge turbulence in fusion plasma

27.05.2020 | Physics and Astronomy

Upwards with the “bubble shuttle”: How sea floor microbes get involved with methane reduction in the water column

27.05.2020 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>