Neutron Star fragments?


by waterfall
Tags: fragments, neutron, star
waterfall
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#1
Feb11-12, 07:13 PM
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Neutron star is said to have masses so compact that 10 miles of it would have more mass than the sun. For example two neutron star collides, can a small fragment be separated from it forming a meteor? And if a small piece were to enter earth atmosphere and reach land. Would the neutron star as small as ping pong ball be stable enough to keep as a collection?
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DaveC426913
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#2
Feb11-12, 07:16 PM
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Quote Quote by waterfall View Post
Neutron star is said to have masses so compact that 10 miles of it would have more mass than the sun. For example two neutron star collides, can a small fragment be separated from it forming a meteor? And if a small piece were to enter earth atmosphere and reach land. Would the neutron star as small as ping pong ball be stable enough to keep as a collection?
No. It is compact because of the massive gravity. Once separated from all that mass, it will not stay compact. Essentially, matter ejected from a neutron star would explode into gas and dust.
alexg
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#3
Feb11-12, 08:31 PM
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Given the massive gravity, it's not likely that any ejecta could leave the surface.

phyzguy
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#4
Feb11-12, 08:35 PM
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Neutron Star fragments?


As DaveC said, if neutron star material gets torn loose from the star, it de-compresses into ordinary atoms. In fact, there is a hypothesis that the heaviest elements on the Earth, known as r-process elements, may have been formed from material torn loose from neutron stars during the merger of two neutron stars. Here's a link:

http://arxiv.org/abs/1105.2453
Chronos
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#5
Feb12-12, 12:56 AM
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Bad news for scifi fans, 'neutronium' and refrigerator light fairies are equally probable in the real universe.
waterfall
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#6
Feb12-12, 08:03 AM
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I guess the only good collector item meteorites are matter made up of strangelets. This is because antimatter meteor can explode even before impact as it touch the oxygen in the atmosphere.. but how come the Tuguska meteor was able to reach near land.. and didn't impact in the clouds when it got in contact with water vapor?
DaveC426913
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#7
Feb12-12, 09:11 AM
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Quote Quote by waterfall View Post
I guess the only good collector item meteorites are matter made up of strangelets. This is because antimatter meteor can explode even before impact as it touch the oxygen in the atmosphere.. but how come the Tuguska meteor was able to reach near land.. and didn't impact in the clouds when it got in contact with water vapor?
There is no reason to suppose the Tunguska meteor was anything more than a garden variety comet or meteor that exploded in the atmo. There's lot's of fanciful hypotheses about antimatter or micro black hole blah blah but no basis for it.
Oldfart
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#8
Feb12-12, 10:17 PM
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Quote Quote by waterfall View Post
Would the neutron star as small as ping pong ball be stable enough to keep as a collection?
If I had this in my collection, how could I support it for viewing?
Chronos
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Feb12-12, 10:25 PM
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You would need to recruit a refrigerator light fairy to keep it stable.
cepheid
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#10
Feb12-12, 11:27 PM
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Quote Quote by Chronos View Post
Bad news for scifi fans, 'neutronium' and refrigerator light fairies are equally probable in the real universe.
I don't understand, can you elaborate? I thought that "neutronium" was just a term for matter that is made entirely of neutrons, and that this term was used mostly in sci-fi and very rarely by actual scientists.

We believe that neutron stars (save for their outermost layers) are made up entirely of neutrons, and thus would qualify for being described as "neutronium" objects (if anyone actually used this term outside of sci-fi). I thought we had pretty good evidence that neutron stars exist in the "real" universe.

Or are you just saying that man-made objects, constructed from "solid neutronium", and hence being super strong, (as depicted in sci-fi), cannot exist, precisely because there is no ridiculously strong gravity to keep the neutrons as neutrons, and they will spontaneously decay into protons and electrons?
Oldfart
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#11
Feb12-12, 11:39 PM
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Quote Quote by Chronos View Post
You would need to recruit a refrigerator light fairy to keep it stable.
What I was getting at was how could I support its weight...?
Chronos
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#12
Feb13-12, 12:38 AM
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Degenerate matter relies on the enormous gravitation of its parent 'star' to stabilize it. If you try to excise any of it from the gravitational field, it will not be pretty.
mjacobsca
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#13
Feb13-12, 12:47 AM
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This topic was discussed a bit last year. Here's the link:

http://www.physicsforums.com/showthread.php?t=485500
Chronos
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#14
Feb13-12, 01:00 AM
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Bear in mind a 'free' neutron has a half life less than 15 minutes. Neutron stars obviously survive much longer than that.
stevebd1
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#15
Feb13-12, 01:15 AM
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While neutron degenerate matter isn't considered stable outside the gravitation field of a neutron star, it's predicted that strange quark matter might be-
..Comparison of the energy per baryon of 56Fe and nuclear matter with the energy per brayon of 2-flavour (u, d quarks) and 3-flavour (u, d, s quarks) strange quark matter. Theoretically the energy per baryon of strange matter may be below 930 MeV, which would render such matter more stabe than nuclear matter.
http://arxiv.org/abs/astro-ph/0407155 page 19 fig 11.


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