New simulations suggest runaway stars may be outcasts from binaries

November 18, 2011 by Bob Yirka report

(PhysOrg.com) -- For at least half a century, astronomers have been perplexed by so-called runaway stars; big monsters that hurtle around galaxies at some thirty kilometers per second without apparent reason. Now however, astrophysicists Michiko S. Fujii and Simon Portegies Zwart describe in their paper published in Science, how they believe that the big stars get their speed as a result of being hurled out and away from binary star couplings that occur within the centers of clusters of stars.

The two suggest that on occasion some big stars move close enough to binaries (paired stars) that they get pulled into their , resulting in an unbalanced state as the trio moves awkwardly through space. After some time passes, the big star gets the boot and as a result of the buildup of energy created between the three, is sent hurtling out into space, becoming a runaway star.

Such stars have been the focus of much attention as they travel so much faster than all the other stars around them. Most in the by contrast plod along at a measly five kilometers per second, so it’s not difficult to see why the speedsters would draw so much attention. Prior to this research, some suggested the big stars got their speed from being near another star that exploded. Other’s theorized that they’d maybe simply paired with another star and the two began moving around one another at a faster clip, similar to ball room dancers. Though in this case, the two would have wound up flinging one another apart in opposite directions in their grand finale.

To back up their theory, Fujii and Zwart built a computer simulation of star clusters and found that over time each did indeed include binaries that attracted other stars that were eventually sent packing by the original two. The researchers believe this proves that the majority, if not all runaway stars became such due to being rejected as a temporary third mate for binaries.

This new thinking came about when two stars last year were spotted speeding away from a dense group of star clusters believed to be less than two million years old, which seemed to fly in the face of the exploding partner idea, as such stars aren’t thought to explode until reaching at least three million years of age.

At any rate, as time passes, it should be easy enough to prove this new theory; all scientists have to do is trace back the trajectories of speeding to see if they came from identifiable binaries.

Explore further: Hubble Sees Star Cluster 'Infant Mortality'

More information: The Origin of OB Runaway Stars, Published Online November 17 2011. Science DOI: 10.1126/science.1211927 www.sciencemag.org/content/early/2011/11/16/science.1211927

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5 comments

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Jonseer
1 / 5 (1) Nov 18, 2011
what about Individual stars from one of the dwarfs in the process of being consumed by the Milky Way that could hit the galactic plane going perpendicular or reverse the typical galactic rotation?
omatumr
1 / 5 (7) Nov 20, 2011
This new thinking came about when two stars last year were spotted speeding away from a dense group of star clusters


Thanks for the story.

If the centers of clusters of stars are massive neutron stars, then runaway stars may be like fission fragments created by repulsive forces between neutrons [1,2].

1. "Neutron Repulsion", The APEIRON Journal, in press (2011)
http://arxiv.org/...2.1499v1

2. "Is the Universe Expanding?" Journal of Cosmology 13, 4187-4190 (2011)
http://journalofc...102.html

With kind regards,
Oliver K. Manuel
Former NASA Principal
Investigator for Apollo
http://myprofile....anuelo09
jsdarkdestruction
2.3 / 5 (3) Nov 21, 2011
Oliver Manuel's recent efforts to plaster Physorg.com and other public news sites with his theories and personal URLs are a bit puzzling, as scientists have a variety of publications available to communicate directly to each other in. My best guess is that he is desperately trying to prop up his legacy in light of his arrest in his university office on 7 charges of rape and sodomy based on allegations by 4 of his own children. The charges have been reduced to one count of felony attempted sodomy, not necessarily because of his innocence, but because of the statute of limitations. One can only guess how the recent charges and decades of family strife have affected his ability to reason rationally and to remain objective while defending his unpopular theories.

http://mominer.ms...hildren/

http://www.mshp.d...mp;first
Ethelred
4.3 / 5 (6) Nov 21, 2011
Thanks for the story.
It wasn't a story Oliver. Stories are what you do.

, then runaway stars may be like fission fragments created by repulsive forces between neutrons [1,2].
So neutron repulsion can overcome 3 billion gravities? How did the star form in the first place if that is true?

According to you Neutron repulsion stops the formation of Black Holes. If Black Holes are stopped by NR then Neutron stars couldn't exist either. Of course there are all those claims that NR is causing galaxies to fragment and you spammed the site with that dozens of times.

If it has the range to fragment galaxies and the strength and range to block the formation of ANY black holes then it not only is strong enough to stop the formation of neutron stars but also ANYTHING that is held together by gravity.>>
Ethelred
4.3 / 5 (6) Nov 21, 2011
For NR to stop the formation of Black Holes and cause the fragmentation of galaxies and even Neutron Stars then it is stronger than gravity at both the range of a dozen kilometers and at kiloparsecs. This means that not only does it shatter galaxies but they could not form in first place. Planets could not form and ALL gravity bound objects would be sundered by this hypothetical galaxy busting Black Hole blocking force.

Ethelred

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