Warp-Speed Planets?

This topic was created by dssf .

  1. dssf

    Warp-Speed Planets?

    " Planets in tight orbits around stars that get ejected from our galaxy may actually themselves be tossed out of the Milky Way at blisteringly fast speeds of up to 30 million miles per hour, or a fraction of the speed of light, a new study finds.

    "These warp-speed planets would be some of the fastest objects in the galaxy, aside from photons and particles like cosmic rays," said Avi Loeb, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "In terms of large, solid objects, they would be the fastest. It would take them 10 seconds or so to cross the diameter of the Earth."

    In 2005, astronomers found evidence of a runaway star that was flying out of the Milky Way galaxy at a speed of 1.5 million mph (2.4 million kph). This hypervelocity star was part of a double-star system that wandered too close to the supermassive black hole at the center of the galaxy.

    The strong gravitational pull at the galactic center ripped the stars apart, sending one hurtling through space at high speeds, while capturing the other to stay in orbit around the massive black hole."

    Hmmm.. this might fuel plausible "Space:1999"-like shoe ideas... Why write of a moon if somehow a whole, populated, advance culture-planet is fodder?

  2. Robert E A Harvey

    Sounds like the advanced culture would be freezing to death quite quickly.

  3. saundby

    Not if they just followed their star out of the galaxy. Think of the view from a bit above and outside of the galactic disk.

    They'd live longer at that speed, too, though they wouldn't necessarily realize it, with everything locally travelling at the same pace.

    1. Anonymous Coward
      Anonymous Coward

      Even if they were as close to their sun as Mercury is to ours then they'd be too far apart to follow their star at such high accelerations (and you need really high accelerations to get up to such high speeds).

      1. C. P. Cosgrove

        Follow your star ?

        I must respectfully disagree with LeeE about the planets being left behind.

        If this speed crazy star is belting along because the other half of its binary system was caught by a black hole, then the forces involved would have acted on the planets as well. If the planetary orbits were narrow relative to the binary orbit, then the forces acting on the planets would be essentially the same as the forces acting on the star. I could see relatively minor differences in the effect on the orbits of the planets depending on where they were relative to the binary at the time of break up, but I would expect the planets to trundle along with Mama Star.

        Chris Cosgrove

        1. Anonymous Coward
          Anonymous Coward

          Re: Follow your star ?

          The magnitude of the force acting upon the star would not be the same as the magnitudes of the forces acting upon orbiting planets. For the star to be accelerated to such a high degree it would have to closely approach the BH but at such close distances the gravitational gradient is so steep that there would be considerable differences between the forces that the star and any orbiting planets would experience.

          For example, if the planet is orbiting its star at 0.5 AU (a bit further out than Mercury is from Sol) and the star then passes the BH at a distance of 1.0 AU (the distance of Earth's orbit around Sol) then the force acting upon the planet will be between 4x and 1/3rd the force acting upon the star, depending upon their relative positions. The only way that they would experience the same magnitude of force is if they were to pass either side of the BH, which would still leave them heading off in different directions.

  4. C. P. Cosgrove

    Follow your star - further

    Mmmm . . . Not entirely convinced.

    The origin of this thread suggests that one half of a binary system was captured to stay in orbit, while the other was ejected from the galaxy.

    If the binary system was a very close one, then, as I understand it, stable planetary orbits are very unlikely in the first place. If the binary system was separate enough to permit the existence of planets, then I submit that, at some orbital confugurations at least, the difference in forces acting on the system around one of the stars would be much lower than you suggest since the whole system would be further away. A binary system can be considered in shape as a dumbell. if the 'bar' is perpendicular to the close contact with a BH, the forces acting on the far end will be much lower than the forces acting on the near end.

    Chris Cosgrove

    1. Anonymous Coward
      Anonymous Coward

      Re: Follow your star - further

      I agree that stable planetary orbits are very unlikely in a close binary star system but a relatively distant binary system isn't going to work either because, whichever way you look at it, the star that is accelerated out of that system must pass relatively close to the BH, and into a relatively steep gravity gradient, to achieve that acceleration.

      The only point I was actually disagreeing with was a previous post that suggested that a planet could follow its star in such an encounter. The original article was about isolated 'warp-speed' planets, not 'warp-speed' systems, and it's precisely because the planets are stripped from their systems in a close encounter with a BH that they occur. The article also mentions runaway stars and it's quite possible that some of these stars originally had planets; if the planets weren't sucked into the BH during the encounter then they would very likely end up as 'warp-speed' planets. They would wouldn't be heading in the same direction and at the same speed as the star though.

  5. C. P. Cosgrove

    Follow your star - no further !

    OK, game set and match to LeeE.

    I don't really disagree with you, the concept seems highly unlikely. It made for some cracking SF stories though. Unhappily I don't have time at the moment to dig through my collection of Analogs from the '60s and '70s - a souvenir of my youth - to dig out some references.

    Chris Cosgrove

  6. Anonymous Coward
    Anonymous Coward

    A word from a stargazer on a passing warped solar system...


  7. Rambler

    would certainly spice up the Sky At Night :o)

    and trying to get a snapshot of THAT wee beastie as it blasted past

    one last, if you COULD see it, and it was BLUE, would it be too late to build THE rocket to take us to a safe place :o)

  8. Anonymous Coward
    Anonymous Coward

    Cool stuff

    Or hot.

    "Heellp.. Usss.. (whoosh)"

    On the flip side, expect much FTL research to be done by inhabitants of said planet when they find they are on a collision course to a star or black hole.

  9. Anonymous Coward
    Anonymous Coward

    Written in english. Abc theoryes''!

    Hello all. Here I want to say, that I have a solution to one and the problems of mathematics in number theory. In addition, using (ABC hypothesis) from, the this problem, you can check whether there are a lot of prime numbers or not, and check these numbers. To find a solution to this equation, you need to search for them for a long time, but if you want, you can do it. This is my solution to the task,of these problem"s, for this you need 1 + a = 23 ^ 8, so "the problem is where rad is less than c", you must use the hypothesis rule, finding a prime number a, b their sum will be less than the extent to which I have indicated, and there are many such numbers, for this you need to use odd numbers up to 37. For this you need to use the same degree as me, and starting from num 17. Everything on this one, while goodbye, ciao.

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