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How Neutron Stars Get Their Kicks
mustermark writes: "Now we may know why neutron stars zip through space at 1000 times the speed of a normal star. Massive stars have been shown to collapse aspherically, and chunks blown off in this process may recoil the neutron-star remnant in the opposite direction."
Holy moly, galactic billiards!
I'm going to have to get down to the Patent Office and get dibs on that... but first, Tau Ceti in the corner pocket.
I particularly enjoyed the dateline.
"Jun 19, 2000 - ROCHESTER, N.Y. -- When a massive star runs out of nuclear fuel something extraordinary happens in the space of a few seconds: The star's core collapses from a radius of 1,000 miles into a tight, dense ball."
Wow, all that happens here in Rochester?
Jeez. I really have to get over to the University of Rochester more often then!
|/usr/games/fortune
NightHawk
Tyranny =Gov. choosing how much power to give the People.
You sir, give Anonymous Cowards the world around, a bad name.
As the star collapses, if one side is less dense than the other gravity will cause the density gradient to increase. This insures that when it expels matter more matter is expelled on one side than the other. I guess it would be possible to have a star that's density is so balanced that no gravitational gradiant will be produced, but the odds of this happening is so insanely low that stars ALWAYS get a density gradient and therefore always get a kick when they are formed.
Understanding the mechanics of the universe is important because it increases our knowledge of science in general. It may not be clear right now how understanding something that happens thousands of light years away (and therefore took place thousands of years ago) may be useful. But one day it will be useful. After all at first studying the planets didn't seem that useful but Newton used planetary motion when he was fathering classical physics.
A closely matched binary system would trade accretion until the soon to be Neutron was orbiting a further away, but rapidly falling towards the slightly denser soon to be Nova. If the quasi Neutron star was far enough away when big brother lost his top, the shockwave, and infalling matter would actually push it to "ludicrous speed".
If the quasi neutron star was too close... well, it would still move (if not destroyed) but its chances of growing into an adult Neutron.
Any Accretion pulled off of the nova'd star would be stripped while moving, and the star would begin it's decay into a Neutron.
krystal_blade
It will be easy to motivate our fellow man; there is hardly anything people treasure more than not being annihilated.
Yeah, and the Earth is flat! After all, if it were round we would fall off. Constellations do change though quite slowly (when compared to the length of human life.)
I've got an idea: here is a book -- read it!
Gee, all this I just thought that Neutron stars were neurotic (thus causing the other stars to shun them). No, seriously though. Someone above mentioned that stars don't move. Well, that is obviously quite false. However, unbeknownst to whover wrote that, he actually did bring up an interesting topic. Do all stars move? We would say yes, but there is no objective way to say. Theoretically, assuming a central point from which all stars originated, all stars should be moving. However, theory does not a fact make. It is quite possible that some stars are perfectly stationary, and yet we perceive htme as moving based on our own positioning in the universe. Our solar system/galaxy moving, therefore perceived motion elsewhere. Since there aren't really any signs in the Universe that say "I am perfectly stationary, measure from me", we have to just make assumption about everything else's mation. I propose that we use our own sun to measure the motion of everything else. After all, it is the most relevant "mile marker" for us earthlings, isn't it? This system would enable us to measure travel/velocity of all observable objects, and in a way that would be relevant to us here on Earth (or even on Mars, Venus, or any other planet in the system). What do you guys think?
Jaeger
http://334.se2600.org
http://jump.to/jaeger
Hydrogen atoms have 1 proton and 2 nuetrons.
Most hydrogen atoms have merely 1 proton and no neutrons. A small percentage has 1 proton and 1 neutron, and this is called deuterium. An even rarer (the rarest) configuration is 1 proton and 2 neutrons, this is called tritium and is radioactive.
So, with Cosmic Inflation, coupled with moderate interest levels, people are gonna start lookin for other means of entertainment. (Do you know how much it costs to get a supernova light show?) Plus, there's always the tickets to those special event horizons, that everyone seems so hyped up on. And lets not forget that since the discovery of the Cosmic Background Radiation, everyone wants a microwave.
Everyone's gotta PAY for that stuff, and some people are being super dense, and writing rubber checks their atomic structure can't cash. Eventually, all those star banks get pissed, and they send in Guido, the Neutron Star to clear things up. He's got the gravity for Repo jobs, and the speed to get things done quickly... He probably carries around one of those Accretion(tm) golf clubs too, just in case.
There's just no getting around the speed this guy needs to get his job done, since nothing travels faster than a bounced check. And you think those black holes got any money? Hell no... They sucked down both theirs, and a whole lotta other paychecks during "binge week". Give em Guido Neutrono... He'll bust their kneecaps.
krystal_blade
It will be easy to motivate our fellow man; there is hardly anything people treasure more than not being annihilated.
Space is my favorite subject. More space stuff guys! Especially about black holes.
OK, this article left me with one question... If these neutron stars accelerate due to matter being blown off the star, and assuming that this matter being blow off is less than the mass of the star, the expelled matter would obtain an acceleration greater than the remainder of the star.
....Paul
So, if the neutron star is going so fast, how fast is the stuff it's blowing off going?
More importantly, where is it going?
Oops, that's two questions isn't it? DOH!!! Three!
F U NE X N M? Son: "Dad... How do you spell 'hourly'?" Dad: "0 * * * *"
Nope, no cookie for you...
Fruit flies like bananas... Time flies like the wind...
and chunks blown off in this process may recoil the neutron-star remnant in the opposite direction
this theory has more applications than simply explaining the motion of neutron stars. for instance, i've often wondered when i'm bent over the toilet bowl blowing chunks after a huge drinking session, why my head recoils in the opposite direction, and everything else seems to be moving 1000 times faster than i am. now i know thanks to this new theory.
And why am i having a hard time believing you've even had sex??? Or am i just associating you with the typical /. reader??? :)= ===
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If ignorance is bliss, wipe the smile off my face
Mooniacs for iOS and Android
This theory has been in place for a long time. It is a well known fact that neutron stars are often moving with high velocities. Many such objects have had their proper motions (angular velocities) measured. It is also known that supernova remnants (the guts of a star after it explodes at the end of its life) are not spherical. This is the topic of research that I work on. To answer a question above I have measured motions in supernova remnants that vary by over a factor of two. That is, one side may be moving at 5,000 km/s and the other may be moving at 2,000 km/s. One can also see much more rich structure in the kinematics of these complex objects. For instance, I have found material moving inwards! Now that certainly is not a spherical explosion!
In his Hitchhiker's Guide to the Galaxy he describes how a little mistake with Galactic Billiards caused billions of deaths when an inhabited planet was accidentally potted into a nearby black hole.
)O(
the Gods have a sense of humour,
Never underestimate the power of stupidity
To err is human, to moo bovine
I don't know who was first between the two, but Grant Naylor also wrote this into an episode of Red Dwarf. (Is it White Hole? I forget...)
In that episode, they use a solar flare to knock a 'cue' planet out of orbit with the goal of clogging up some space thing (white hole?) with it so it won't suck in the ship.
Comment of the year
Just thought some of you might like a more in-depth look at neutron stars. I've been doing some reading on neutron stars in the last few days, so I hunted around in my browser's history and found the two articles I had been reading.
The first one, by New Scientist, is a neat article on stars and their hunger for the planets around them.
The second one, by Scientific American, is a bit technical, but it describes how the X-ray emissions from neutron stars are being used to estimate their size.
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There was a Dangermouse episode about aliens whacking planets into a black hole too ("So would the moon have counted as 4 points away?" asks Penfold). Not sure if it was before or after the Hitchikers joke. certainly before Red Dwarf though... And yes the Red Dwarf Episode was White Hole
Why was London always so deserted in the Dangermouse cartoons? It was like someone had let off an air strike above it, wiping out all of the population except for Dangermouse's HQ under the post box (is that right?). And it was Baron Greenback, Nero and Stiletto right?
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Jon E. Erikson
Jon Erikson, IT guru
Lad, you don't seem to understand the fundamentals of astronomy. Although a neutron star might seem inert, the core falls in on itself, and it releases its stored heat in the form of ghostlike particles called neutrinos. As the neutrinos zig-zag out of nuclear fuel something extraordinary happens in the magnetic field that surrounds the newly formed neutron star. After that, the core becomes denser than the other side and then, form peculiar objects with properties of binary pulsar systems. Moreover, many recent observations have revealed that supernovae are not symmetrical in shape!Neutron stars, one group of which are called pulsars, are the cause - the accretion process is well known. This is the fundamental reason for the non-inertness with regard to motive frequency.
"A few atoms won't even light a match" - Dr Jones, 1933
They move so fast because they are always farting. In space you can really let loose because no one can here you fart. Discuss.
Gaelen
Well, since Hitchhiker's Guide was first out in the late '70s to early '80s, I suspect it came before Dangermouse.
...phil
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
Riiiiiiight. And the Earth is only 6000 years old?
In a time of universal lies, Telling the Truth is a revolutionary act - George Orwell
Once over the inital shock and utter rejection of that statement as complete ignorance or a really poor joke, I realized that in fact it is more logically correct to say that stars are stationary. If you first recognize that the concept of not moving only exists as a relative term from a human perspective, then you see that indeed stars do not move.
What I find interesting is that this points out how the definition of fact changes drastically from one reference frame to another.
g_blow_chunks();
I'm not sure what the memory requirements for a neutron star are though - probably quite high.
--- Hot Shot City is particularly good.
I'm not surprised. I know several people from upstate NY, and most of them are pretty dense.
(duck, run, hide)
Those fine institutions in Rochester and Troy excepted of course.. Heh.
-- What you do today will cost you a day of your life.
..this is, of course, nit-picking.
But here's a thought: why is time not relative? Everything in the universe (that we know of) travels in the same direction at the same rate through time. Is time the one constant in a relative world?
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Philosophy, like masturbation, is something everyone does, but most of the time it's just too awkward to talk about.
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Pay no attention to the errors in my post. I am the great and powerful Oz.
Hrm.. Motion is relative.. there is no motion without a frame of reference.. The difference in the rates at which two seperate observers travel through time is a function of their velocities relative to each other.
Here's something I wonder.. the idea that the speed of light is a limit on how fast something can travel seems to be at odds with the notion of the relativity of motion.
Ex:
(1) - relatively motionless (v = 0 m/s)
(4)... -1/2 lightspeed the other way (v= -0.5c)
QUESTION: Isn't (3) exceeding lightspeed relative to (4), but not to (1) or (2)? What happens at this point? Is there a fault in my logic?
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Pay no attention to the errors in my post. I am the great and powerful Oz.
Quick... drink lots of beer and wave your towel. It's the only way to prepare for space flight...
Fruit flies like bananas... Time flies like the wind...
Well, it is all about frames of reference. If your frame of reference only includes the earth and one star, and the distance between both is changing, then, you can logically say either:
Up to now, what you have said can be right.. NOW, if we include 2 stars and the earth in a frame of reference, and star 1 is moving away from the earth (w/ respect to the earth), star 2 is moving towards the earth (wrtte), and star 1 is moving away from star 2 (w/ respect to either star 1 or star 2) , your options now are: None of the possibilities now have BOTH stars motionless, that's where the problem lies.. unless all stars in the world are glued onto a matt, and some god slides the matt around, you are wrong.. Sorry!
"Producing satire is kind of hopeless because of the literacy rate of the American public."
I just pooped your party.
Yeah, DanBari admits his ignorance, and feels bad that he has trashed the rest of Slashdot's society. Perhaps we should form a monastary of Science and conduct experiments involving stars that travel.
Fruit flies like bananas... Time flies like the wind...
I wonder whether it would be possible to detect a neutron star that is moving toward our solar system at a speed of say 2000km/s and the spin of that star is parallel to our viewing point so that the ejection beams can not be detected (the pulse can not be detected), wouldn't it be neat if a neutron star passed by Earth and maybe even hit it, or any other planet, or even the Sun? I defenetely would love to see the special effects!
You can't handle the truth.
The rest of the above is gibberish.
OTOH, we are talking about tiny, tiny asymmetries:
- A supernova relases 10^51 ergs in mass motion and optical display, 10^53 ergs if you count neutrino emission.
- A neutron star has a mass of ~1.4 times our Sun's mass: to make it travel at 700km/second takes only 10^49 ergs.
So you see, even the fastest neutron stars we know of (the Guitar nebula, for example, is created by a pulsar going ~1600km/sec) use only a tiny fraction of the energy of a supernova.And still, even that tiny fraction takes explaining - but if we buy into hypernovae that create Gamma Ray bursts, then this is a trivial problem.
Sigh - its annoying to reduce your thesis proposal to a trivial problem!
Learn more here...
"I will take the Ring," he said, "though I do not know the way."
The point that I was trying (unsuccessfully) to make was more philosophical than scientific. I was trying to say that everything is moving in some sense, and that we are left only with a practical interpretation of immobility. And in this, practicality is how directly something relates to a person's perceptions.
Relative to the distance between stars and the length of time of human observation, stars can be considered immobile, just as we consider the shifting techtonic [sp!?] plates unmoving.
I'm an astronomer, and one area I do research in is the asymmetries of SNe. Actually, some supernovae appear to have asymmetries on the order of 30%. This is inferred from polarization measurements that we've done. One of these days I'll write up a story about it for starstuff.org (I am actually the co-creator of the site, though I didn't write this neutron star article), but for now you can see the gory details at: http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bi bcode=1999astro.ph.12033W&db_key=PRE&hig h=3845e365b719527 You can also see signs of SN asymmetries in the fact that man SN remnants aren't round. We've even been able to watch the evolution of the layers blown off of the closest supernova in a long time, SN 1987A. Check out: http://oposite.stsci.edu/pubinfo/PR/97/03.html Hope this clears up that comment.
...any theories about the material moving inwards? Secondary explosions? Fascinating, really...
I have explained it as being due to interaction with the external medium. If you have a much lower density on one side of the supernova remant than the other it will set up a pressure gradient within the remnant which pushes material to the less dense side. This has been confirmed through numerical hydrodynamic simulations.
As the neutrinos zig-zag out of the hot (hundreds of billions of degrees) neutron star, they interact with the neutron star matter via the so-called weak interaction, the force responsible for radioactivity. Because the intense magnetic field can polarize the matter, more neutrinos will be emitted along the direction of the magnetic field than opposite to it.
They should rename it to be The Galactic Fart theory
Feed The Need[goatse.cx]
I thought you might have meant it in that way.. but I just had to make sure =)
Oh, and I agree with you, but I thought a scientific approach might be more clarifying than a philosophical-type one.
"Producing satire is kind of hopeless because of the literacy rate of the American public."
I just pooped your party.
Who's years are you referring to?