Skywatch

  • August 19, 2010

    Episode 291: Galaxy Ejects Star

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    Researchers are keen to understand the distribution of matter in the universe, and understanding our own galaxy is a key to this puzzle. By observing the motions of stars in our own galaxy, the distribution of material can be determined. In such studies, a few very fast "hypervelocity" stars have been found. A new Hubble Space Telescope observation indicates that one of these stars has been ejected from the center of the Milky Way in a bizarre scenario. The object was originally part of a multiple-star system, and one component was trapped in the galaxy's core, while the other two were ejected and eventually merged into the object we see today.