Superstar Is the Remnant of a Three-Star System Mangled by a Black Hole

A hypervelocity star appears to be the remains of a three-star system, one star of which was digested by the Milky Way's black hole, with the other two being combined and hurled away. Cynthia Graber reports

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Here’s what scientists think happened, oh, about a hundred million years ago. There was this three-star system. The three linked stars were strolling through the Milky Way but got too close to the giant black hole at the center. The hole swallowed one of those stars and hurled away the other two. Those two careening stars merged to form one super-hot, incredibly fast-moving blue star, which is now on the very outskirts of the Milky Way.

And here’s how scientists came up with that dramatic tale, which they just published in Astrophysicial Journal Letters. [Warren Brown et al., http://bit.ly/aSLafm]

They discovered what they call a hypervelocity star, which moves three times faster than our sun does through the galaxy. According to new information provided by the Hubble telescope, the star originated deep within the Milky Way.


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The scientists used the Hubble to figure out the direction of the star’s travels and the distance from the galactic center, along with the star’s mass, age and speed. Its unusual attributes give rise to the idea that one star was swallowed and transferred its momentum to the other two, which transformed into a blue superstar. Hurtling through the galaxy, faster than a speeding sun.

—Cynthia Graber

[The above text is an exact transcript of this podcast.]

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