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Star Cluster Ejected From Galaxy At 2,000,000 MPH

Posted by Soulskill on from the get-out-and-stay-out dept.

William Robinson writes: "According to a new report, a globular cluster of several thousand stars (compressed into a space just a few dozen light-years apart) is being thrown out of galaxy M87. The cluster, named HVGC-1, is traveling at a rate of 2 million miles per hour. The discovery was made by Nelson Caldwell of the Harvard-Smithsonian Center for Astrophysics and his team while studying the space around the supergiant elliptical galaxy M87. Caldwell and colleagues think M87 might have two supermassive black holes at its center. The star cluster wandered too close to the pair, which picked off many of the cluster's outer stars while the inner core remained intact. The black holes then acted like a slingshot, flinging the cluster away at a tremendous speed."

5 of 133 comments (clear)

  1. Velocity by dtmos · · Score: 5, Interesting

    Two million miles per hour is less than 0.003c, but still quite a clip, even in astronomical terms.

    Since they're discussing velocity (vector speed), and not just speed, the headline is correct in saying " -1000 km/s" when the measured value is -1025 km/s, but one can debate whether the abstract is correct in saying "an extraordinary blueshift of -1025 km/s", rather than "an extraordinary blueshift of 1025 km/s", since "blueshift" gives one the sign of the velocity already.

    1. Re:Velocity by pr0t0 · · Score: 5, Interesting

      I wonder if the Earth was in orbit around a star that was part of such a cluster, would we notice the effects of such an ejection? Certainly the night sky would change, but the whole process could take of millions of years. Would we feel any immediate effects from the proximity to the black holes? What would our current state of technology, instrumentation and measurement tell us about our relative place and speed? And what, if any change would there be in our civilization's future. Not being in the galaxy seems isolating, but if the host star remains unchanged perhaps there is no change in our destiny. Or perhaps that by the time we developed interstellar travel we'd be too far from the host galaxy to travel to anything other than the stars in our cluster.

      It'd make for a good sci-fi book I think.

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    2. Re:Velocity by skastrik · · Score: 5, Interesting

      Frederik Pohl's The World at the End of Time deals with the ejections of solar systems on a grand scale.

  2. They didn't pay the rent? by tekrat · · Score: 4, Interesting

    A cluster of stars were "thrown out" of galaxy M87?... what, they didn't pay the rent? Or is M87 expressing a case of "tough love"?

    The real question is; by what force were they ejected from the galaxy? The fastest we've ever been about to propel something is 24,000 mph -- and that's with a lot of gravity assists.... if we could figure out how to get a spacecraft to 2 million mph, trips around our solar system would go a lot faster.....

    --
    If telephones are outlawed, then only outlaws will have telephones.
  3. Another Question by Mapleperson · · Score: 4, Interesting

    Another questions is what happens to the speeding cluster if is was flung out by a bigger galaxy. One would assume the the dark matter that originally present in the cluster would not take the same track. Without the supporting dark matter the radial velocities are too great for the outer stars of the cluster to continue orbiting the system. One would think that there should be trail of stars left behind. Could be a great way to investigate dark matter interaction with galaxies.