Subscribe free to our newsletters via your
. 24/7 Space News .




STELLAR CHEMISTRY
NASA Delivers New Insight into Star Cluster Formation
by Staff Writers
Washington DC (SPX) May 12, 2014


Stars are often born in clusters, in giant clouds of gas and dust.

Using data from NASA's Chandra X-ray Observatory and infrared telescopes, astronomers have made an important advance in the understanding of how clusters of stars come into being.

The data show early notions of how star clusters are formed cannot be correct. The simplest idea is stars form into clusters when a giant cloud of gas and dust condenses. The center of the cloud pulls in material from its surroundings until it becomes dense enough to trigger star formation. This process occurs in the center of the cloud first, implying that the stars in the middle of the cluster form first and, therefore, are the oldest.

However, the latest data from Chandra suggest something else is happening. Researchers studied two clusters where sun-like stars currently are forming - NGC 2024, located in the center of the Flame Nebula, and the Orion Nebula Cluster. From this study, they discovered the stars on the outskirts of the clusters actually are the oldest.

"Our findings are counterintuitive," said Konstantin Getman of Penn State University, University Park, who led the study. "It means we need to think harder and come up with more ideas of how stars like our sun are formed."

Getman and his colleagues developed a new two-step approach that led to this discovery. First, they used Chandra data on the brightness of the stars in X-rays to determine their masses. Then they determined how bright these stars were in infrared light using ground-based telescopes and data from NASA's Spitzer Space Telescope. By combining this information with theoretical models, the ages of the stars throughout the two clusters were estimated.

The results were contrary to what the basic model predicted. At the center of NGC 2024, the stars were about 200,000 years old, while those on the outskirts were about 1.5 million years in age. In the Orion Nebula, star ages ranged from 1.2 million years in the middle of the cluster to almost 2 million years near the edges.

"A key conclusion from our study is we can reject the basic model where clusters form from the inside out," said co-author Eric Feigelson, also of Penn State. "So we need to consider more complex models that are now emerging from star formation studies."

Explanations for the new findings can be grouped into three broad notions. The first is star formation continues to occur in the inner regions because the gas in the inner regions of a star-forming cloud is denser -- contains more material from which to build stars -- than the more diffuse outer regions. Over time, if the density falls below a threshold where it can no longer collapse to form stars, star formation will cease in the outer regions, whereas stars will continue to form in the inner regions, leading to a concentration of younger stars there.

Another idea is that old stars have had more time to drift away from the center of the cluster, or be kicked outward by interactions with other stars. One final notion is that the observations could be explained if young stars are formed in massive filaments of gas that fall toward the center of the cluster.

Previous studies of the Orion Nebula Cluster revealed hints of this reversed age spread, but these earlier efforts were based on limited or biased star samples. This latest research provides the first evidence of such age differences in the Flame Nebula.

"The next steps will be to see if we find this same age range in other young clusters," said Penn State graduate student Michael Kuhn, who also worked on the study.

These results will be published in two separate papers in The Astrophysical Journal and are available online. They are part of the MYStIX (Massive Young Star-Forming Complex Study in Infrared and X-ray) project led by Penn State astronomers.

.


Related Links
spitzer.caltech.edu
Spitzer at NASA
Chandra at NASA
chandra at SI
Stellar Chemistry, The Universe And All Within It






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








STELLAR CHEMISTRY
Galaxy's biggest telescope used to make precise measurement of spinning star
Perth, Australia (SPX) May 08, 2014
An international team of astronomers has made a measurement of a distant neutron star that is one million times more precise than the previous world's best. The researchers were able to use the interstellar medium, the 'empty' space between stars and galaxies that is made up of sparsely spread charged particles, as a giant lens to magnify and look closely at the radio wave emission from a ... read more


STELLAR CHEMISTRY
Russia to begin Moon colonization in 2030

Saturn in opposition tonight, will appear next to the moon

LRO View of Earth

Astrobotic Partners With NASA To Develop Robotic Lunar Landing Capability

STELLAR CHEMISTRY
Opportunity In Search Of Aluminum-Hydroxyl Clays

Against the current with lava flows

NASA wants greenhouse on Mars by 2021

Reset and Recovery for Opportunity

STELLAR CHEMISTRY
Chris Hadfield's 'Space Oddity' video to be taken off YouTube

'Convergent' Research Solves Problems that Cross Disciplinary Boundaries

Pioneering Test Pilot Bill Dana Dies at Age 83

More Plant Science as Expedition 39 Trio Trains for Departure

STELLAR CHEMISTRY
The Phantom Tiangong

New satellite launch center to conduct joint drill

China issues first assessment on space activities

China launches experimental satellite

STELLAR CHEMISTRY
Three astronauts land back on Earth in Soyuz capsule

Expedition 39 Trio Wrapping Up Six Months on Station

Russia to only use ISS until 2020: official

Ham video premiers on Space Station

STELLAR CHEMISTRY
Replacing Russian-made rocket engines is not easy

Pre-launch processing begins for the O3b Networks satellites

US sanctions against Russia had no effect on International Launch Services

SHERPA launch service deal to deploy 1200 kilo smallsat payloads

STELLAR CHEMISTRY
New Exomoon Hunting Technique Could Find Solar System-like Moons

Odd planet, so far from its star

Length of Exoplanet Day Measured for First Time

Spitzer and WISE Telescopes Find Close, Cold Neighbor of Sun

STELLAR CHEMISTRY
China aids in cutting down space debris

Space junk problem discussed

Exelis advancing sensor detection system

Airbus Defence and Space in radar technology study




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.