Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 


Forgot your password?
Close
typodupeerror
×
Space Science

Dead Star Set to Escape the Milky Way 132

Posted by Zonk from the ware-the-undead dept.
slackah wrote to mention a NewScientist.com article discussing a fast-moving stellar corpse on its way out of our galaxy. From the article: "The object, called B1508+55, is a rotating neutron star, or pulsar. It is the superdense core of a massive star that exploded as a supernova about 2.5 million years ago. The explosion seems to have ejected the pulsar with such force that it will eventually escape the Milky Way entirely, says team member Shami Chatterjee, an astronomer with NRAO and CfA."
This discussion has been archived. No new comments can be posted.

Dead Star Set to Escape the Milky Way More

Dead Star Set to Escape the Milky Way

Comments Filter:

  • Rogue star (Score:1, Funny)

    by theufo ( 575732 )
    I wonder how long before Bush declares war...
  • I wonder if it has a trench..

  • Tracking (Score:4, Insightful)

    by nounderscores ( 246517 ) on Saturday September 03, 2005 @03:20AM (#13469188)
    I wonder how long we can track this object once it leaves the galaxy. Any perturbations of its path will tell us about the dark matter between galaxies and the gravitational pull such putative dark matter exerts.

    • Comment removed (Score:4, Funny)

      by account_deleted ( 4530225 ) on Saturday September 03, 2005 @03:27AM (#13469210)
      Comment removed based on user account deletion

    • Re:Tracking (Score:5, Insightful)

      by 1u3hr ( 530656 ) on Saturday September 03, 2005 @04:31AM (#13469369)
      I wonder how long we can track this object once it leaves the galaxy. Any perturbations of its path will tell us about the dark matter

      Fast, for a star, but it's 1/300th of c. So it'll be at least 300,000 years to get 1000 ly out, getting to the edge of the galaxy. By then we'll either be extinct or know all about the dark matter.

    • Insighful (Score:1, Insightful)

      by Anonymous Coward
      The earth will be long dead, come on show a little knowledge.
      • in only 300,000 years?

        That's still a blink of an eye compared to the billions it's been around.
        • Ahem, WE haven't been around for billions, only 10 thousand years of recorded history, one thousand years of advanced technology and 100 years of electronic technology, I bet we can achieve the destruction of earth to tiny bits in 300,000 years easily. Just believe in us. We can do it. Come on guys, yes, we can!

  • Galaxies must be a lot more dynamic than I thought (Score:4, Interesting)

    by Hannah E. Davis ( 870669 ) on Saturday September 03, 2005 @03:26AM (#13469206) Journal
    This kind of thing makes me wonder how static the current shape of our galaxy is. Do stars (dead or otherwise) leave all the time, and do they ever come in from somewhere else? Do ejected stars form the cores of new galaxies? I doubt we'll ever get a chance to see much of this in action anyway since the galaxy in general moves so slowly, but it's still neat.

    It also occurs to me that this isn't really news: depending on how far away the star is/was, there's a fair chance that it left our galaxy millions of years ago :)
    • Not millions - the Milky Way has only about hundrend of thousands of lightyears in size. So at least some of our ancestors could see it when it was in our galaxy for sure. If neanderthalls are our ancestors, of course.
    • http://www.npaci.edu/online/v4.9/galaxies2.html [npaci.edu]


      for what it's worth, here's a simulation of Our milky way hitting Andromeda.

      Things like this happen all the time.

    • Re:Galaxies must be a lot more dynamic than I thou (Score:4, Interesting)

      by Markus Registrada ( 642224 ) on Saturday September 03, 2005 @12:30PM (#13471213)
      depending on how far away the star is/was, there's a fair chance that it left our galaxy millions of years ago

      7700 years, anyway, according to the article.

      But it's never a good idea to take these announcements at face value. It's far from clear the thing has anything to do with a supernova, or that it's a neutron star at all -- presuming any of them exist at all. What we do know is that its light (radio, x-rays, etc.) pulses at a rate too fast for them to understand unless it's a tiny thing spinning.

      The reason they insist it has to be something spinning is that they have studied almost no plasma fluid dynamics, so they can't understand something blasting out radio, light, and x-rays that doesn't have a star in the middle of it. They don't understand fluid instabilities and current oscillations, so they're at a complete loss to understand the (quite common) sudden, often temporary changes in oscillation rate in pulsars.

      What little they have studied, typically, is a trivial approximation to plasma fluid dynamics known as "magneto- hydro-dynamics" (MHD) which assumes space is superconducting and magnetic fields can't change distribution or strength. (They talk in all earnestness of magnetic fields "frozen" in place -- even in the sun!) Therefore, they can't understand how large flows of charged particles -- currents, which they insist on calling "jets" -- produce their own magnetic fields and flow along them, or how these flows' fields can interact in marvelously complex ways.

      Everything you read about "dark matter", "supermassive black holes", and "neutron stars" amounts to a desperate attempt to find some way to make the extremely weak and purely attractional gravity account for the complicated things they see. The mathematics behind plasma fluid dynamics is too hard for them, and they just can't stand that. It makes their press releases funny to read, but it's sad, too. (Think of the lives wasted on planetary epicycles.)

      • They don't understand fluid instabilities and current oscillations...

        ...and you do. Wonderful. Now, why don't you publish a paper so we can all share your remarkable insight? I'm sure you'll be given a Nobel Prize for it.

        • "... why don't you publish a paper so we can all share your remarkable insight? I'm sure you'll be given a Nobel Prize for it."

          There are plenty of papers published by serious plasma researchers. Astrophysicists don't read them. That's what makes it sad, but it's also what makes the press releases positively comical.

          Birkeland currents have been studied for more than a century, ever since they were elucidated as the process behind the Aurora Borealis. Next time you meet an astrophysicist, ask why Birke

        • Sarcasm or merely inarticulate you're missing the point. Electric, magnetic, and electromagnetic forces are largely IGNORED by the astrophysics community despite their obvious importance. Said forces figure in combustion of gas in a bunsen burner in highschool, not that you'd ever hear it from your teacher because orthodox science is possessed of orthodoxy that says it isn't important.

          They ARE important, and beyond the simplistic things that astrophysicists deign to deal with like the Coulomb Barrier in s
      • But it's never a good idea to take these announcements at face value. It's far from clear the thing has anything to do with a supernova, or that it's a neutron star at all -- presuming any of them exist at all. What we do know is that its light (radio, x-rays, etc.) pulses at a rate too fast for them to understand unless it's a tiny thing spinning.

        The reason they insist it has to be something spinning is that they have studied almost no plasma fluid dynamics, so they can't understand something blasting
        • Leaving aside ad-hominem remarks...

          ...Professor Thomas Gold, of Cornell University ... showed that the pulses had regular patterns which would only arise from a process where a driving momentum was continuously stabilizing the signal ...

          Evidently the only thing that could carry that much momentum must be neutronium, because it has to be imagined physically tiny. That model fails, though, to account for recently discovered pulsars that would have to spin fast enough to break up even a neutron star. W

  • You know your life is sad... (Score:4, Funny)

    by Dogun ( 7502 ) on Saturday September 03, 2005 @03:27AM (#13469212) Homepage
    when you find yourself envying a neutron star.
  • If only my parents had been creative enough to give me a name as cool as B1508+55!
    • If your parent was the biblical Abraham, then you would have as many brothers and sisters as the stars in the sky and the sand in the sea.

      Of course, we'd end up naming you fairly boring and common names like David and Sarah.
      • Back in Biblical times, all names had meaning. That's why you see things like, "She named her son $FOO because $BAR." David, as an example, is "the beloved," and I'm quite happy having it as my middle name.

  • Amazing (Score:3, Interesting)

    by Cash202 ( 854642 ) <cash202@gmail.com> on Saturday September 03, 2005 @03:31AM (#13469218)
    How interesting and spectacular.....

    Strange how one can be so impressed by something, he knows so little about...

    The concept of escaping the galaxy is awsome, but it would be nice to know more about it...

    So I did some research: Milky Way Galaxy is: ~100,000 light years in diameter; ~3,000 light years in thickness; ~250,000 light years in circumference.

    Basically, its huge. The ratio of our solar system to the milky way galaxy is 1:65,000,000.

    From this I believe that just about anything can escape the galaxy, it would just take an extremely long time. However, as I have stated, my knowledge on the subject is limited, so it is possible that the planets and stars are arranged in such a way, that the gravitational pull would always redirct any object to go back. (i.e.: meteors and asteroids pass Earth in patterns and intervals, without leaving the galaxy).

    The subject is very interesting, and if someone could bring more light on it, it would be helpful...

    • You're right, the fact the galaxy exists is because the planets and stars orbit the galactic core.

      It is exceptional that something got the escape velocity to leave the galaxy in a kind of time frame that we're able to see it happen in.

      This pulsar is the new speed record holder for an object of its class.

    • Re:Amazing (Score:5, Funny)

      by meringuoid ( 568297 ) on Saturday September 03, 2005 @05:05AM (#13469441)
      Milky Way Galaxy is: ~100,000 light years in diameter; ~250,000 light years in circumference.

      Wow. I knew we had a central black hole, but I didn't realise it distorted space that much. What value is the pi where you live?

    • From this I believe that just about anything can escape the galaxy, it would just take an extremely long time.
      You need to look at the concept of "escape velocity". There are two ways to approach this concept - as an expression of a time series of decreasing velocities, or on an energetics basis. The energy basis is simpler to explain - consider that an object moving in a gravitational field has a particular amount of kinetic energy as a consequence of it's motion. The same object would require a certain amo

  • In other news... (Score:5, Funny)

    by elgatozorbas ( 783538 ) on Saturday September 03, 2005 @03:37AM (#13469233)
    Dard Vader not amused
  • That's no moon. It's a space station

  • Comment removed (Score:4, Funny)

    by account_deleted ( 4530225 ) on Saturday September 03, 2005 @03:51AM (#13469264)
    Comment removed based on user account deletion

    • Re:Did anyone else... (Score:2, Funny)

      by Anonymous Coward
      Oh! You misread the title in an unexpected way and posted about it! Haha! Everyone quick, mod this guy up!
    • "Don't be too proud of this technological terror you've created. The ability to leave the Milky Way is insignificant next to the power of the Force."

      (My God... that's the second consecutive post I've made on /. consisting of just a modified Star Wars quote...)
    • Yes but then I figure it couldn't be because they say specifically : "In a galaxy FAR AWAY". So the Death Star was never in our galaxy in the first place.
    • I didn't, but I wondered which movie actor was sending his/her ashes into cosmos now. (And how the heck they got that far out.)

  • Cool (Score:2)

    by Devar ( 312672 )
    I want to hitch up with the civilization that is using that thing as a ride outta this dump! :)
  • The story explains that the force of the supernova appears to have accelerated the stars core away from our galaxy and that soon it will move out... but if there was an "explosion" surely the stars core would be at the CENTRE of the explosion, so relative to the rest of the galaxy the force exerted on the star by the supernova would be pretty much zero (cancel itself out by pushing in all directions at once)...?

    Anyone care to explain it to a long-time-ago astrology student?

    • Re:How is this possible? (Score:3, Informative)

      by Burz ( 138833 )
      Many supernovas are asymmetric. The net effect is that the remaining core receives a sideways "kick".

    • Re:How is this possible? (Score:5, Informative)

      by imsabbel ( 611519 ) on Saturday September 03, 2005 @05:06AM (#13469443)
      The main point is: the core isnt EXPLODING, its COLLAPSING to a neutron star. The "explosion" is just a rebounce off the core (_slightly_ simplified :) ).

      After the collapse, the kinetic energy of the quasi free falling neutron matter will overcompress the neutron star core, and then it will oscillate.

      As the collapse istn something perfectly symetrical, there will be significant amplitude of the first harmonic of the oscillation. Thus (for example) the matter hitting the star on one hemisphere will have the core expanding in their direction with quite some speed, while the other side will see it receeding). As the impact isnt very long, there wont be time to average out. In the moment the hull impacts, the core will "push" itself away from that quasi-spherical shell thats hitting it.

      (you have to remember: there is significant mass in that shell. Only a small part of the star actually ends of in the neutron star, so there IS enough mass in the hull for conservation of momentum)
      • An other explanation of a fast star leaving the galaxy is a 'slingshot' trajectory close to some other star. One of the stars would loose energy (and fall towards the galactic center) and the other would gain energy and possibly achieve escape velocity.

        The slingshot principle has been used for a number of spacecrafts and there is a number of trajectories which could transfer momentum between two objects traveling in a common gravity well (e.g. galaxy or solar system).

        Yours Yazeran

        Plan: To go to Mars one day

        • I know, i know. Had to calculate such a slingshot in lagrange coordinates years ago, its a bitch...
          But for neutron stars:

          Calculate the odds for such a slingshot, and the needed trajectories....

          1000km/s is FAST, the other partner would need to be a black hole to get speeds like that ( a normal star wouldnt survive, but merge with the neutron star).
          The crossection is SO small, the needed target so rare, the needed deltaV so large, thats there not much chance of something like this happening in a galaxy ever.
          • Well i guess i stand corrected... :-) I hadent done the math, but only speculated that in principle it is possible.. :-)

            Yours Yazeran

            Plan: To go to Mars one day with a hammer.
          • The crossection is SO small, the needed target so rare, the needed deltaV so large, thats there not much chance of something like this happening in a galaxy ever...

            You are forgetting the super-massive black hole in the center of the galaxy, and any black-holes (or neutron-stars) which may very probably be in orbit around it. (lookup AGN - active-galactic nuclei)

            In fact, I'm not sure that the slingshot option isn't rather more probable than the fast-supernova-remnant hypothesis. Remember that the star-dens
    • Somehow, I don't think astrology has anything to do with this.

      At least I hope that our destinies will not be affected by the fact that a dead star is leaving our galaxy.

    • "Anyone care to explain it to a long-time-ago astrology student?"

      Astrology?

      Hmmm.

      Okay, this may suit you...

      For an explanation of how neutron stars achieve such high speeds, read the first chapter of Robert L Forward's _Dragon's Egg_. It fills in all the actual details missing from TFA.

      Go on... look in Wiki. You know you want to!
    • "Anyone care to explain it to a long-time-ago astrology student?" It is leaving the galaxy because it's horoscope said "if you are considering it, now would be a good time to move"

  • Thats nothing unususal (Score:5, Informative)

    by imsabbel ( 611519 ) on Saturday September 03, 2005 @04:47AM (#13469402)
    Those neutron stars are the product of stellar cores collapsing into a neutron star (and then sheding the outer hull thats impacting on the core rebounce shockwave in a class II supernova).

    Now if such a collapse isnt absolutly symetrical, there will be higher spherical hermonics in the neutron core oszillation, and thus the impact of the hull on the core will give it a random impuls vector (the first harmonic being the 2 hemispheres oszilating with 180degree phase difference).

    The observation of those fast moving neutron stars helped the understanding of this processes, as there isnt much that can accelerate them after their creation to this speeds.

    A common speed of a class2 supernova product is in the 100-1000 km/s range (about 2 orders of magnitures lower than the speed of the the ejected hull, thus the visible SNR still seemingly have the neutron star in the center), which is way enough for most to leave our galaxy (300 or so is needed)
    • Those neutron stars are the product of stellar cores collapsing into a neutron star you're kidding! I thought those neutron stars were the product of stellar cores collapsing into a almond crusted colby yule log.

  • OMG (Score:3, Funny)

    by ZeroExistenZ ( 721849 ) on Saturday September 03, 2005 @05:44AM (#13469494)
    Dead Star Set to Escape the Milky Way

    OMG! DON't LET IT GET AWAY! SEND THE AMERICANS TO RETRIEVE IT!

    ON second thought.. I slightly recall the "retrieving"-abilities of the US army and some guy who's bin pretty laden.

  • In other news, the star in question was said to have been heard screaming, "Watch out, that mad candy bar has rabies!!!"
  • Elvis Presley has left the galaxy.

  • Has to be done (Score:3, Funny)

    by Conspiracy_Of_Doves ( 236787 ) on Saturday September 03, 2005 @07:11AM (#13469698)
    Radio transmissions have been detected from an area in space outside of our galaxy that lies on the star's path. When decoded, a voice could be heard to say:

    "Bring out your dead!"
  • Yet another fine example of galactic garbage disposal system working properly. Roger Wilco's involvement is rumored, although StarCon declined to confirm it.
  • It is a giant spaceship transferring aliens out of our galaxy before it meets its fate with the Andromeda galaxy. We should follow them soon!
  • Slow-moving corpses are bad enough, but fast-moving ones are just scary! I still haven't gotten 28 Days Later out of my head!
  • This sounds a bit like a dupe or just old news, I've heard it before. Of course it really is *really* old news, but.. um.

    Anyway it would be nice to project its path ahead to see what civs need bailing out. Then NASA's warp drive project has a goal! Maybe we should keep our scopes and neutrino detectors on that region of space to see if any other civs already have mounted a hypervelocity rescue effort? Note the star is seen 7000 years in the past, so it is actually 20 light years or so closer to its vict
  • We are lucky that in this case life does not imitate art precisely. Read Nemesis by S. Lem for reference.

  • Jeez, we gotta get a cooler name for our galaxy. The Zornax Spiral or something. Anything.
  • For those of you who stink at stellar metric measures, like me, Google knows all:
    1 100 (kilometers per second) = 2 460 629.92 miles per hour

    Damn.

  • Anyone up for ride ? (Score:2, Interesting)

    by McSpace ( 884897 )
    Now this is a good opportunity to calculate the probable escape velocity of our own galaxy.
  • This is a star, even if it is a dead one. I wonder if it is pulling anything out with it? A planet, asteroids, or anything like that. On that note, what will it do to us? could it slightly change any of our orbits or the sun's path through space? Just a philosopher's thoughts.

Slashdot Top Deals

Some people manage by the book, even though they don't know who wrote the book or even what book.

Close