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 NASA detects solar flare pulses at Sun and Earth
17.11.2017 | NASA/Goddard Space Flight Center

nachricht Pluto's hydrocarbon haze keeps dwarf planet colder than expected
16.11.2017 | University of California - Santa Cruz

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: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>