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 When fluid flows almost as fast as light -- with quantum rotation
22.06.2018 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences

nachricht Thermal Radiation from Tiny Particles
22.06.2018 | Universität Greifswald

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: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>